{
  "spore": "profile",
  "id": "smco",
  "spore_version": "0.2",
  "family": "magnet-and-superconducting-alloys",
  "name": "Samarium-cobalt sintered magnet alloy",
  "abbreviation": "SmCo",
  "role": "permanent magnet",
  "category": "metals",
  "type": "magnet-alloys",
  "summary": "Sintered samarium-cobalt is the high-temperature rare-earth magnet family. It comes in two phases: SmCo5 (the 1:5 alloy) and Sm2Co17 (the 2:17 alloy). Eclipse Magnetics gives a Curie temperature of 800 to 850 degC for Sm2Co17 and rates standard grades to 300 degC, and 350 degC for the H grades. Arnold's Recoma 35E datasheet gives a nominal remanence of 1.190 T and a Curie temperature of 820 degC. Sm2Co17 is weaker than NdFeB at room temperature but often outperforms it above 150 to 180 degC. It is brittle and corrodes in wet conditions unless it is coated. The NASA Glenn review of radiation effects reports that Sm2Co17 magnets showed no measurable flux change after neutron fluences near 1e20 n/cm2 in one reactor test.\n",
  "best_for": "Strong magnets that must stay stable above 150 degC, with a rated limit of 300 to 350 degC for Sm2Co17 grades (Eclipse)",
  "weakest_at": "Room-temperature strength against NdFeB, brittleness (flexural strength 110 to 120 N/mm2), and surface corrosion of Sm2Co17 in water without a coating",
  "identity": {
    "formula": "SmCo5 (1:5 phase) and Sm2Co17 (2:17 phase)",
    "designations": [],
    "source": "wiki-smco",
    "where": "Composition section: SmCo5 has one samarium atom per five cobalt atoms, and Sm2Co17 has two per 13 to 17 transition-metal atoms (Wikipedia)"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "total-radiation-dose",
      "extreme-heat"
    ],
    "applications": [
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, SmCo 22 (1:5 grade)",
      "value": 9.2,
      "value_high": 9.6,
      "bound": "range",
      "unit": "kGs",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 22 (Sm1Co5 phase)",
        "value_type": "typical range, approximate"
      },
      "method": "Typical range in the supplier's grade table (the sheet says values are approximate and for reference only)",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 22, Br column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, SmCo 26 (2:17 grade)",
      "value": 10.2,
      "value_high": 10.5,
      "bound": "range",
      "unit": "kGs",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26 (Sm2Co17 phase)",
        "value_type": "typical range, approximate"
      },
      "method": "Typical range in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26, Br column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, Recoma 35E (Sm2Co17)",
      "value": 1.19,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E",
        "value_type": "nominal (minimum 1.170 T)"
      },
      "method": "Value listed in the manufacturer datasheet (11,900 Gauss nominal)",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Magnetic Properties table, Br Residual Induction, nominal column",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "coercivity_hcb",
      "label": "Normal coercivity HcB, SmCo 26",
      "value": 9.4,
      "value_high": 10,
      "bound": "range",
      "unit": "kOe",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26",
        "value_type": "typical range, approximate"
      },
      "method": "Typical range in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26, HcB column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity HcJ, SmCo 26 (standard)",
      "value": 18,
      "bound": "lower",
      "unit": "kOe",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26",
        "value_type": "minimum"
      },
      "method": "Minimum listed in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26, HcJ column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity HcJ, SmCo 26H (high-coercivity grade)",
      "value": 25,
      "bound": "lower",
      "unit": "kOe",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26H",
        "value_type": "minimum"
      },
      "method": "Minimum listed in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26H, HcJ column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity HcJ, Recoma 35E (Sm2Co17)",
      "value": 1800,
      "bound": "exact",
      "unit": "kA/m",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E",
        "value_type": "nominal (minimum 1710 kA/m)"
      },
      "method": "Value listed in the manufacturer datasheet",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Magnetic Properties table, HcJ Intrinsic Coercivity, nominal column",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_energy_product",
      "label": "Maximum energy product (BH)max, SmCo 26",
      "value": 24,
      "value_high": 26,
      "bound": "range",
      "unit": "MGOe",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26",
        "value_type": "typical range, approximate"
      },
      "method": "Typical range in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26, BH Max column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "max_energy_product",
      "label": "Maximum energy product (BH)max, Recoma 35E",
      "value": 265,
      "bound": "exact",
      "unit": "kJ/m3",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E",
        "value_type": "nominal (minimum 255 kJ/m3)"
      },
      "method": "Value listed in the manufacturer datasheet",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Magnetic Properties table, BHmax Maximum Energy Product, nominal column",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Sm1Co5 phase",
      "value": 700,
      "value_high": 750,
      "bound": "range",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Curie Temperature Sm1Co5, Tc",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Sm2Co17 phase",
      "value": 800,
      "value_high": 850,
      "bound": "range",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Curie Temperature Sm2Co17, Tc",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Recoma 35E (Sm2Co17)",
      "value": 820,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E"
      },
      "method": "Value listed in the manufacturer datasheet",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Thermal Properties, row Curie Temperature Tc",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum recommended temperature, Sm1Co5",
      "value": 250,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)",
        "condition": "maximum recommended working temperature"
      },
      "method": "Value listed in the manufacturer datasheet (Max Working Temperature box)",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Max Working Temperature box, row Sm1Co5 (1:5)",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum recommended temperature, Sm2Co17 standard grades",
      "value": 300,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17), standard grades",
        "note": "L grades +250 degC, H grades +350 degC"
      },
      "method": "Value listed in the manufacturer datasheet (Max Working Temperature box)",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Max Working Temperature box, row Sm2Co17 (2:17), +250 (L) / +300 / +350 (H)",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum working temperature, SmCo 26H (Sm2Co17 H grade)",
      "value": 350,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 26H"
      },
      "method": "Value listed in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 26H, Max Temp column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Max recommended use temperature, Recoma 35E",
      "value": 300,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E"
      },
      "method": "Value listed in the manufacturer datasheet",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Thermal Properties table, row Max. Recommended Use Temperature",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_br",
      "label": "Reversible temperature coefficient of Br, SmCo 22 (1:5 grade)",
      "value": -0.045,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "SmCo 22 (Sm1Co5 phase)",
        "value_type": "approximate, reference only"
      },
      "method": "Value listed in the supplier's grade table",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Magnetic Properties of Samarium Cobalt table, row SmCo 22, alpha Br column",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_br",
      "label": "Reversible temperature coefficient of Br, Recoma 35E (Sm2Co17)",
      "value": -0.035,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E",
        "range": "20 to 200 degC"
      },
      "method": "Value listed in the manufacturer datasheet (note 1)",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Other Properties table, row Reversible Temperature Coefficient of Induction alpha(Br), note 1",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_hcj",
      "label": "Reversible temperature coefficient of coercivity, Recoma 35E (Sm2Co17)",
      "value": -0.25,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "Recoma 35E",
        "range": "20 to 200 degC"
      },
      "method": "Value listed in the manufacturer datasheet (note 1)",
      "status": "ground",
      "source": "arnold-recoma35e",
      "where": "Other Properties table, row Reversible Temperature Coefficient of Coercivity alpha(Hcj), note 1",
      "source_detail": {
        "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
        "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Sm1Co5 phase",
      "value": 8.2,
      "value_high": 8.4,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Density Sm1Co5",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Sm2Co17 phase",
      "value": 8.3,
      "value_high": 8.5,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Density Sm2Co17",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "cte",
      "label": "Thermal expansion parallel to the c axis, Sm2Co17",
      "value": 8,
      "value_high": 10,
      "bound": "range",
      "unit": "1e-6 per degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)",
        "direction": "parallel (C//)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Coefficient of Thermal Expansion Sm2Co17, C//",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "cte",
      "label": "Thermal expansion perpendicular to the c axis, Sm2Co17",
      "value": 11,
      "bound": "exact",
      "unit": "1e-6 per degC",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)",
        "direction": "perpendicular (C perp)"
      },
      "method": "Value listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Coefficient of Thermal Expansion Sm2Co17, C perpendicular",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, SmCo magnet alloy",
      "value": 11.6,
      "value_high": 12.8,
      "bound": "range",
      "unit": "W/m degC",
      "scope": "material",
      "conditions": {
        "material": "samarium cobalt magnet alloy",
        "temperature": "not stated"
      },
      "method": "Range listed in the supplier's physical-properties table (approximate)",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Physical Properties of Samarium Cobalt table, row Thermal Conductivity",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat, SmCo magnet alloy",
      "value": 370,
      "bound": "exact",
      "unit": "J/(kg degC)",
      "scope": "material",
      "conditions": {
        "material": "samarium cobalt magnet alloy",
        "temperature": "not stated"
      },
      "method": "Value listed in the supplier's physical-properties table (approximate)",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Physical Properties of Samarium Cobalt table, row Specific Heat",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, Sm2Co17 phase",
      "value": 450,
      "value_high": 500,
      "bound": "range",
      "unit": "Hv",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)",
        "load": "D.P.N. (diamond pyramid number)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Vickers Hardness Sm2Co17, Hv D.P.N.",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, Sm1Co5 phase",
      "value": 500,
      "value_high": 600,
      "bound": "range",
      "unit": "Hv",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)",
        "load": "D.P.N. (diamond pyramid number)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Vickers Hardness Sm1Co5, Hv D.P.N.",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "flexural_strength",
      "label": "Flexural strength, Sm2Co17 phase",
      "value": 110,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)",
        "unit_as_printed": "N/mm2",
        "test": "not stated"
      },
      "method": "Value listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Flexural Strength Sm2Co17",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "flexural_strength",
      "label": "Flexural strength, Sm1Co5 phase",
      "value": 120,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)",
        "unit_as_printed": "N/mm2",
        "test": "not stated"
      },
      "method": "Value listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Flexural Strength Sm1Co5",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus, Sm2Co17 phase",
      "value": 1.2,
      "bound": "exact",
      "unit": "10^11 N/m2",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)"
      },
      "method": "Value listed in the manufacturer physical-properties table (printed as 1.2 x 10^11 N/m2)",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Young's Modulus Sm2Co17",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus, Sm1Co5 phase",
      "value": 1.6,
      "bound": "exact",
      "unit": "10^11 N/m2",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)"
      },
      "method": "Value listed in the manufacturer physical-properties table (printed as 1.6 x 10^11 N/m2)",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Young's Modulus Sm1Co5",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "label": "Poisson's ratio, SmCo magnet alloy",
      "value": 0.27,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "material": "samarium cobalt magnet alloy",
        "temperature": "not stated"
      },
      "method": "Value listed in the supplier's physical-properties table (approximate)",
      "status": "ground",
      "source": "allstar-smco-tech",
      "where": "Physical Properties of Samarium Cobalt table, row Poisson's Ratio",
      "source_detail": {
        "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, Sm2Co17 phase",
      "value": 80,
      "value_high": 90,
      "bound": "range",
      "unit": "uohm cm",
      "scope": "material",
      "conditions": {
        "phase": "Sm2Co17 (2:17)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Electrical Resistivity Sm2Co17",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, Sm1Co5 phase",
      "value": 5,
      "value_high": 6,
      "bound": "range",
      "unit": "uohm cm",
      "scope": "material",
      "conditions": {
        "phase": "Sm1Co5 (1:5)"
      },
      "method": "Range listed in the manufacturer physical-properties table",
      "status": "ground",
      "source": "eclipse-smco",
      "where": "Physical characteristics table, row Electrical Resistivity Sm1Co5",
      "source_detail": {
        "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Humid or wet conditions, uncoated Sm2Co17",
      "headline": "Sm2Co17 can rust at the surface in water. A NiCuNi coating is the usual remedy.",
      "effect": "The low free iron content in Sm2Co17 makes it technically prone to a little surface corrosion when in water. The supplier recommends a NiCuNi coating for wet environments. Its corrosion resistance is rated good to very good, far superior to NdFeB, in most applications.",
      "rating": "moderate",
      "conditions": {
        "phase": "Sm2Co17 (2:17)",
        "exposure": "wet environments; no quantified corrosion rate in the source"
      },
      "source": "eclipse-smco",
      "where": "Corrosion Resistance panel"
    },
    {
      "environment": "Humid applications, Sm1Co5 (no iron)",
      "headline": "Sm1Co5 has excellent corrosion resistance because it contains no iron.",
      "effect": "The supplier says Sm1Co5 contains no iron and has excellent corrosion resistance, and that SmCo magnets can usually be used in humid applications without a protective coating. No humidity test result is given.",
      "rating": "low",
      "conditions": {
        "phase": "Sm1Co5 (1:5)",
        "exposure": "humid applications; no test duration or humidity level stated"
      },
      "source": "eclipse-smco",
      "where": "Corrosion Resistance panel"
    },
    {
      "environment": "Acidic, alkaline or electrically conductive liquids, and powder in air",
      "headline": "Acids release hydrogen from the magnet material. Powder oxidises in air.",
      "effect": "The safety data sheet says hydrogen is released in contact with acid and can cause explosive gas mixtures. It says to avoid exposing powdered magnet material to air or oxygen, and to avoid acidic, alkaline or electrically conductive liquids. No corrosion rate is given.",
      "rating": "unknown",
      "conditions": {
        "exposure": "contact with acid; powder exposed to air; no quantified rate"
      },
      "source": "allstar-smco-sds",
      "where": "Section 10 Stability and Reactivity, items 10.3 to 10.5"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Cobalt (PubChem CID 104730): signal word Danger. Notified hazards include H317 (over 99.9% of notifications), H334 (over 99.9%), H341 (65.8%), H350 (64.5%), H360Fd (61.6%) and H413 (54.9%). PubChem says 1 of 2768 reports does not meet GHS criteria. Cobalt is also listed by the supplier as IARC 2B (possibly carcinogenic).",
        "ghs": [
          "H317",
          "H334",
          "H341",
          "H350",
          "H360Fd",
          "H413"
        ],
        "source": "pubchem-cobalt",
        "where": "GHS Classification section"
      },
      {
        "text": "Samarium (PubChem CID 23951): signal word Danger. Notified hazards are H228 flammable solid (91%) and H261 in contact with water releases flammable gas (94.1%). PubChem says 6 of 255 reports (2.4%) do not meet GHS criteria.",
        "ghs": [
          "H228",
          "H261"
        ],
        "source": "pubchem-samarium",
        "where": "GHS Classification section"
      },
      {
        "text": "Finished SmCo magnet (Allstar SDS, Rev 1.0, 09 Feb 2024): classification GHS-US is 'Not Applicable'; the sheet says semi-finished and finished products are articles under REACH with no obligation to classify, and no label applies. The sheet's classifications for samarium and cobalt apply to powder form only.",
        "ghs": [],
        "source": "allstar-smco-sds",
        "where": "Sections 2.1, 2.2 and 3.2"
      },
      {
        "text": "Dust and powder: the SDS says dry mechanical processing is allowed only under special precautions, because dusts can self-heat or be pyrophoric, and that dust clouds in air can be explosive. Wet grinding can form hydrogen at room temperature.",
        "ghs": [],
        "source": "allstar-smco-sds",
        "where": "Sections 5.2 and 7.1.1 to 7.1.2"
      }
    ],
    "failure_risks": [
      {
        "mode": "Demagnetisation by heat",
        "trigger": "Use above the grade's maximum recommended temperature, or heating toward the Curie temperature (700 to 750 degC for Sm1Co5, 800 to 850 degC for Sm2Co17)",
        "consequence": "Loss of magnetisation. The rated limits are 250 degC for Sm1Co5, 300 degC for Sm2Co17 and 350 degC for H grades. Eclipse notes that SmCo performs very similarly to N30 at ambient temperature but better above 150 to 180 degC.",
        "severity": "high",
        "source": "eclipse-smco",
        "where": "Max Working Temperature box and opening paragraphs"
      },
      {
        "mode": "Demagnetisation by high-energy particles",
        "trigger": "Proton beams and high-energy particle fields",
        "consequence": "In an earlier French study cited by the NASA review, about 1e16 per cm2 (about 1e9 rad) of 400 GeV protons caused nearly complete demagnetisation of similar SmCo alloys. The review says radiation energy and magnet chemistry both matter, and that Sm2Co17 was more stable than SmCo5 under 500 MeV protons.",
        "severity": "high",
        "source": "bowman-2013",
        "where": "Hard Magnetic Materials and Radiation section"
      },
      {
        "mode": "Brittleness",
        "trigger": "Mechanical impact and handling",
        "consequence": "Flexural strength is 110 N/mm2 for Sm2Co17 and 120 N/mm2 for Sm1Co5 (Eclipse). The supplier says NiCuNi plating is claimed by some to limit chipping, but this is rarely done.",
        "severity": "moderate",
        "source": "eclipse-smco",
        "where": "Physical characteristics table; Corrosion Resistance panel"
      },
      {
        "mode": "Surface corrosion of uncoated Sm2Co17",
        "trigger": "Exposure to water or a wet environment",
        "consequence": "Light surface rust on Sm2Co17, which the supplier says can be avoided with a NiCuNi coating.",
        "severity": "moderate",
        "source": "eclipse-smco",
        "where": "Corrosion Resistance panel"
      }
    ],
    "side_effects": [
      {
        "text": "Magnetic fields from packed magnets can attract magnetisable material and can interfere with pacemakers and other implanted devices; the SDS says people with heart pacemakers must keep away from magnetic fields.",
        "affects": "Handling and shipping of magnetised parts",
        "source": "allstar-smco-sds",
        "where": "Section 7 Handling and Storage and Section 14 Transport"
      }
    ],
    "handling": [
      {
        "text": "Keep the magnets dry and in a place free of corrosive atmosphere, and keep them away from iron, cobalt and nickel objects and high magnetic fields.",
        "source": "allstar-smco-sds",
        "where": "Section 7.2 Storeroom and Receptacle Requirements"
      },
      {
        "text": "For processing: provide filtered ventilation. Cobalt has a 0.1 mg/m3 OSHA permissible exposure limit as Co for metal dust and fume. The SDS recommends a P3 respirator where limits are exceeded.",
        "source": "allstar-smco-sds",
        "where": "Section 8 Exposure Controls"
      },
      {
        "text": "Avoid elevated temperatures above 150 degC for powdered magnet material (the SDS lists this as a condition to avoid). The grade ratings in the properties apply to solid magnets.",
        "source": "allstar-smco-sds",
        "where": "Section 10.4 Conditions to Avoid"
      },
      {
        "text": "Wear gloves when handling magnetised parts or parts with sharp edges, and wear safety glasses during metal processing.",
        "source": "allstar-smco-sds",
        "where": "Section 8.2 Exposure Controls"
      }
    ],
    "mitigations": [
      {
        "text": "Sm2Co17 in wet conditions: a NiCuNi coating is recommended by the supplier to avoid surface corrosion.",
        "source": "eclipse-smco",
        "where": "Corrosion Resistance panel"
      },
      {
        "text": "Higher-temperature grades (H grades, +350 degC) and low-temperature-coefficient grades are available; the LTC versions have less variation in output with temperature.",
        "source": "eclipse-smco",
        "where": "Opening paragraphs and Max Working Temperature box"
      },
      {
        "text": "The NASA review suggests keeping the bulk temperature of irradiated permanent magnets below 50% of the Curie temperature as a design guideline. For Sm2Co17 this is about 400 to 425 degC (half of the 800 to 850 degC Eclipse range; computed here).",
        "source": "bowman-2013",
        "where": "Hard Magnetic Materials and Radiation section; Summary and Conclusions"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Linear alternator in a Stirling space power convertor (nuclear fission power system)",
      "example": "NASA Glenn reviewed how radiation affects the magnets in the linear alternator of a Stirling power convertor, for nuclear-powered space missions.",
      "source": "bowman-2013",
      "where": "Introduction"
    },
    {
      "application": "mechanisms",
      "device": "Motors, sensors, loudspeakers and military systems",
      "example": "The Eclipse datasheet says SmCo magnets are ideal for aerospace, automotive, sensor, loudspeaker, motor and military applications.",
      "source": "eclipse-smco",
      "where": "Opening paragraph"
    }
  ],
  "supply": [
    {
      "subject": "Cobalt",
      "abundance": "World mine production was 310,000 t of cobalt content in 2025 (302,000 t in 2024). Congo (Kinshasa) mined 230,000 t, Indonesia 44,000 t and Russia 7,700 t in 2025. Shares are computed by Space Mushroom from the table (Congo about 74.2%, Indonesia about 14.2%, Russia about 2.5%). World reserves are 12,000,000 t. USGS's own text gives Congo as 73% of the world total.",
      "producers": [
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 74.2,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 14.2,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 2.5,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (cobalt named)",
          "listed": true
        },
        {
          "list": "EU critical raw materials 2023 (cobalt listed)",
          "listed": true
        }
      ],
      "recycling": "Cobalt content of purchased scrap was 25% of estimated US cobalt consumption in 2025 (USGS).",
      "substitutes": [
        "USGS: potential substitutes in magnets include barium or strontium ferrites, and neodymium-iron-boron alloys (USGS)."
      ],
      "source": "usgs-mcs2026-cobalt",
      "where": "Salient Statistics (US), Recycling line, World Mine Production and Reserves table, Substitutes"
    },
    {
      "subject": "Samarium and other rare earths",
      "abundance": "World rare-earth mine production was 390,000 t of rare-earth oxide equivalent in 2025 (380,000 t in 2024). Shares are computed by Space Mushroom from the 2025 column: China 270,000 t (about 69.2%), United States 51,000 t (about 13.1%), Australia 29,000 t (about 7.4%), Burma 22,000 t (about 5.6%). Reserves in China are 44,000,000 t. USGS does not report samarium mine output separately.",
      "producers": [
        {
          "country": "China",
          "share_percent": 69.2,
          "year": 2025
        },
        {
          "country": "United States",
          "share_percent": 13.1,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 7.4,
          "year": 2025
        },
        {
          "country": "Burma",
          "share_percent": 5.6,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (rare earth elements and samarium named)",
          "listed": true
        },
        {
          "list": "EU critical raw materials 2023 (light and heavy rare earth elements listed; samarium not named on the EC page)",
          "listed": true
        }
      ],
      "recycling": "USGS: limited quantities of rare earths were recovered from batteries, permanent magnets and fluorescent lamps.",
      "substitutes": [
        "USGS: substitutes are available for many applications but generally are less effective."
      ],
      "source": "usgs-mcs2026-rare-earths",
      "where": "Salient Statistics, World Mine Production and Reserves table (2025 column), Recycling, Substitutes"
    },
    {
      "subject": "Samarium export controls and stockpile",
      "abundance": "In April 2025 China tightened export controls to cover alloys, compounds, metals and oxides of samarium, gadolinium, terbium, dysprosium and other elements. In November China suspended its October expansion for one year, while the April controls remained in effect, and began issuing general export licences to selected exporters. For FY 2025 the US government's potential stockpile acquisitions included 60 t of samarium-cobalt alloy.",
      "producers": [],
      "critical_lists": [],
      "recycling": "No recycling rate for samarium-cobalt magnets is given in the sources read.",
      "substitutes": [],
      "source": "usgs-mcs2026-rare-earths",
      "where": "Events, Trends, and Issues; Government Stockpile"
    },
    {
      "subject": "Heavy rare earths (EU supply)",
      "abundance": "The European Commission page states that China provides 100% of the EU's supply of heavy rare earth elements.",
      "producers": [],
      "critical_lists": [
        {
          "list": "EU critical raw materials 2023: heavy rare earth elements",
          "listed": true
        }
      ],
      "substitutes": [],
      "source": "ec-crm",
      "where": "Fifth list of critical raw materials (2023) and supply concentration statement"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Eclipse Magnetics Technical Data Sheet: Samarium Cobalt Magnets (SmCo)",
      "type": "datasheet",
      "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf"
    },
    {
      "title": "Allstar Magnetics Samarium Cobalt Technical Data (ASM 09-23-2023)",
      "type": "datasheet",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
      "year": 2023
    },
    {
      "title": "Arnold Magnetic Technologies Recoma 35E sintered samarium cobalt datasheet (Rev. 160204a)",
      "type": "datasheet",
      "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
      "year": 2016
    },
    {
      "title": "Allstar Magnetics Safety Data Sheet: Samarium Cobalt (SDS SMC Rev 1.0, 09 Feb 2024)",
      "type": "sds",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Samarium-cobalt-SDS.pdf",
      "year": 2024
    },
    {
      "title": "NASA Glenn: Design Issues for Using Magnetic Materials in Radiation Environments at Elevated Temperature (NTRS 20130010718)",
      "type": "paper",
      "url": "https://ntrs.nasa.gov/api/citations/20130010718/downloads/20130010718.pdf",
      "year": 2013
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Cobalt",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Rare Earths",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-rare-earths.pdf",
      "year": 2026
    },
    {
      "title": "USGS: About the 2025 List of Critical Minerals",
      "type": "report",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025
    },
    {
      "title": "European Commission: Critical raw materials",
      "type": "report",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "year": 2024
    },
    {
      "title": "PubChem compound records: samarium (CID 23951) and cobalt (CID 104730), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23951",
      "year": 2026
    }
  ],
  "gaps": [
    "No flight, vacuum-outgassing, thermal-cycling or space-qualification result for samarium-cobalt magnets was found in an opened source. The NASA review says no verified models or experimental data exist for predicting magnet behaviour in space power applications.",
    "The Naval Postgraduate School paper (bremsstrahlung irradiation of rare-earth magnets, which the search result describes as ranking Sm2Co17 above SmCo5 above NdFeB) could not be opened: the repository page returned no full text. The ranking is therefore not stated in this profile.",
    "Radiation values in the NASA review are quoted from earlier experiments (Brown 1982, Coninckx, Blackmore, Chen). None were re-measured, and the SmCo5 versus Sm2Co17 comparison is qualitative only in the sources read.",
    "The NASA review's neutron fluences (about 1e18 n/cm2 with negligible loss in Brown et al., and about 1e20 n/cm2 with imperceptible change in Chen et al.) are printed with superscript exponents that the PDF text does not keep, so they appear in the story and risk text only, not as numeric properties.",
    "Eclipse's Sm2Co17 Hci coefficient (-0.20) and Sm1Co5 Br coefficient (-0.050) print trailing zeros that the value check could not match; the Arnold (Sm2Co17) and Allstar (SmCo 22) rows that print the same number exactly are used instead.",
    "No quantified humidity, salt-spray or coating-specific corrosion data for uncoated or NiCuNi-coated SmCo were found in an opened source.",
    "Manufacturing route (powder metallurgy, pressing, sintering and ageing) was not read in a fetched source, so no process entry is given.",
    "Compressive strength, the Recoma 35E specific heat and thermal conductivity values, and the Recoma 35E electrical resistivity (its unit symbol is lost in the PDF text) were not included because the PDF layout is ambiguous for those rows.",
    "Property names not in spores/property-canon.yaml and used here as snake_case: remanence_br, coercivity_hcb, coercivity_hcj, max_energy_product, temp_coeff_br, temp_coeff_hcj, vickers_hardness, neutron_fluence_no_loss.",
    "Atomic weights are PubChem values printed to a few decimals (Sm 150.4, Co 58.93319). No IUPAC table value was read.",
    "Samarium production is not reported separately by USGS; the rare-earth shares are for all rare earths combined. Cobalt and rare-earth shares were computed by this profile from USGS tables.",
    "The composition of a typical commercial SmCo magnet (about 35% Sm and 65% Co by weight) comes from one supplier SDS; grade-by-grade compositions were not read.",
    "The Eclipse table layout is ambiguous in places, so grade-level Eclipse rows for the 2:17 alloy were not used; the Allstar grade table is used for grade values."
  ],
  "story": {
    "why": "Samarium-cobalt (SmCo) is a sintered rare-earth permanent magnet. It was developed in the early sixties by Karl Strnat at Wright-Patterson Air Force Base and Alden Ray at the University of Dayton, according to Wikipedia. Its Curie temperature of 700 to 850 degC and its rated working limits of 250 to 350 degC are the reason it is chosen where heat is the main limit. Its remanence falls by only 0.035% per degC for Sm2Co17. The trade-off is strength at room temperature, where NdFeB is stronger, and brittleness. For radiation, the NASA Glenn review cites Sm2Co17 as the most stable magnet type among those it reports, but it gives no flight data.",
    "uses": [
      {
        "where": "Space power conversion (ground review)",
        "line": "NASA Glenn reviewed radiation effects on the magnets in the linear alternator of a Stirling power convertor for nuclear-powered space missions. The review says no verified models or flight data exist for predicting magnet behaviour in space power applications."
      },
      {
        "where": "Motors, sensors and loudspeakers",
        "line": "The Eclipse datasheet lists aerospace, automotive, sensor, loudspeaker, motor and military applications for SmCo magnets, and calls them an ideal first choice in mission-critical applications."
      },
      {
        "where": "Specialised uses listed by USGS",
        "line": "The USGS 2025 critical-mineral page describes samarium as used in permanent magnets, nuclear reactors and cancer treatments."
      }
    ],
    "can_do": [
      {
        "label": "Remanence",
        "line": "SmCo 26 (Sm2Co17) has a remanence of 10.2 to 10.5 kGs, and Recoma 35E has a nominal 1.190 T (Allstar, Arnold).",
        "scope": "material",
        "value": "10.2 to 10.5 kGs"
      },
      {
        "label": "Working temperature",
        "line": "Eclipse rates Sm2Co17 at 300 degC for standard grades and 350 degC for H grades, and Sm1Co5 at 250 degC. Arnold's Recoma 35E is rated to 300 degC.",
        "scope": "material",
        "value": "300 degC (350 degC for H grades)"
      },
      {
        "label": "Temperature stability",
        "line": "The remanence of Sm2Co17 (Recoma 35E) falls by 0.035% per degC over 20 to 200 degC, against 0.045% per degC for the SmCo 22 (1:5) grade (Allstar).",
        "scope": "material",
        "value": "-0.035 %/degC (Sm2Co17)"
      },
      {
        "label": "Radiation",
        "line": "In a water-moderated reactor test cited by NASA Glenn, Sm2Co17 magnets showed imperceptible flux change after up to about 1e20 n/cm2 of neutrons. Conditions (temperature and magnet shape) are not fully stated, and these are earlier experiments quoted in the review.",
        "scope": "material",
        "value": "Imperceptible change up to about 1e20 n/cm2"
      },
      {
        "label": "Coercivity",
        "line": "SmCo 26H has an intrinsic coercivity of at least 25 kOe, against 18 kOe for SmCo 26 (Allstar). Coercivity is the field the magnet resists before it loses magnetisation.",
        "scope": "material",
        "value": "25 kOe minimum (H grade)"
      }
    ],
    "compare": "Against NdFeB, SmCo is weaker at room temperature but often performs better above 150 to 180 degC, according to the Eclipse datasheet, which also says it is stable over a wide temperature range. In the NASA review's reactor test, the NdFeB samples had no post-irradiation magnetic flux recorded, while Sm2Co17 magnets showed imperceptible change after up to about 1e20 n/cm2. Within SmCo, Sm2Co17 has the higher remanence and rated temperature, and Sm1Co5 contains no iron and so resists humid corrosion better without coating.",
    "compare_rows": [
      {
        "label": "Remanence (SmCo 26)",
        "benchmark": "remanence_br",
        "scope": "material"
      },
      {
        "label": "Maximum working temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      },
      {
        "label": "Curie temperature",
        "benchmark": "curie_temperature",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep Sm2Co17 magnets coated with NiCuNi if they will be in wet conditions.",
      "Do not heat the magnets above the grade's rating: 250 degC for Sm1Co5, 300 degC for Sm2Co17 and 350 degC for H grades.",
      "Dust from machining is a fire and explosion hazard. Use filtered ventilation and avoid creating dust.",
      "Keep pacemaker wearers away from magnetised parts."
    ],
    "good_for": [
      "High-temperature magnets: the rated limit is 300 degC for standard Sm2Co17 and 350 degC for H grades, and the Curie point is above 800 degC.",
      "Radiation-exposed parts where the NASA review reports little change: Sm2Co17 showed imperceptible flux change after the neutron fluence in the cited reactor test.",
      "Humid applications for Sm1Co5, which contains no iron and does not usually need a coating (Eclipse)."
    ],
    "watch_out": [
      "Weaker than NdFeB at room temperature (Eclipse).",
      "Brittle: flexural strength is 110 to 120 N/mm2 (Eclipse).",
      "Sm2Co17 rusts at the surface in water without a NiCuNi coating.",
      "Cobalt is a supply concern: Congo (Kinshasa) mined about 74% of world cobalt in 2025 (computed), and cobalt is on the USGS 2025 critical list.",
      "China's April 2025 export controls cover samarium alloys, compounds, metals and oxides."
    ],
    "verdict": "SmCo is the high-temperature rare-earth magnet: its Curie temperature and rated working temperature are well above NdFeB's, and the NASA review reports little radiation damage for Sm2Co17. Its room-temperature strength is lower than NdFeB's. A NiCuNi coating covers the Sm2Co17 corrosion risk. No space-flight data were found, so its fitness for spacecraft is not proven by these sources.",
    "recipe": {
      "line": "Samarium-cobalt alloys are intermetallic compounds of samarium and cobalt. SmCo5 is the older 1:5 phase, with one samarium atom per five cobalt atoms. Sm2Co17 is the stronger 2:17 phase, with two samarium atoms per seventeen cobalt atoms. Sm2Co17 magnets also contain copper, hafnium and/or zirconium, sometimes praseodymium, and iron. Commercial magnets are sintered, and the Allstar SDS gives a typical mix of about 35% samarium and 65% cobalt by weight. The sintering route itself was not read in a fetched source.",
      "parts": [
        {
          "name": "Samarium",
          "symbol": "Sm",
          "role": "One samarium atom per five cobalt atoms in SmCo5, and two per seventeen in Sm2Co17. Samarium supplies the magnetic anisotropy and most of the coercivity.",
          "atoms": 1,
          "atomic_weight": 150.4,
          "source": "pubchem-samarium"
        },
        {
          "name": "Cobalt",
          "symbol": "Co",
          "role": "The balance of the alloy by weight, about 65% in a typical magnet. Cobalt sets the high Curie temperature and the high-temperature stability.",
          "atoms": 5,
          "atomic_weight": 58.93319,
          "source": "pubchem-cobalt"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The finished magnet is not classified under GHS-US. Hazards come from powder, dust and processing.",
        "points": [
          {
            "label": "Finished magnet",
            "line": "The supplier SDS says the solid magnet is not classified under GHS-US and no label applies."
          },
          {
            "label": "Powder and dust",
            "line": "Dust can self-heat, be pyrophoric or form explosive clouds in air. Wet grinding can release hydrogen."
          },
          {
            "label": "Cobalt",
            "line": "Cobalt is a skin and respiratory sensitiser (H317, H334 in powder form), and the SDS lists it as IARC 2B."
          }
        ],
        "gap": "Safety data sheets for other suppliers were not read.",
        "level": 1,
        "verdict": "Dust and powder are the hazard"
      },
      {
        "title": "If it fails",
        "lead": "The loss of magnetisation depends on grade, temperature and radiation type.",
        "points": [
          {
            "label": "Heat",
            "line": "Above its rated temperature, the magnet loses magnetisation. The rating is 250 degC for Sm1Co5, 300 degC for standard Sm2Co17 and 350 degC for H grades."
          },
          {
            "label": "Particles",
            "line": "In an earlier French study cited by NASA Glenn, about 1e16 per cm2 of 400 GeV protons caused nearly complete demagnetisation of similar SmCo alloys."
          },
          {
            "label": "Corrosion",
            "line": "Uncoated Sm2Co17 can rust at the surface in water."
          }
        ],
        "level": 3,
        "verdict": "Heat and particle radiation demagnetise it"
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage",
            "line": "Keep dry, in a place free of corrosive atmosphere, and away from iron, cobalt and nickel objects."
          },
          {
            "label": "Processing",
            "line": "Use filtered ventilation, avoid dust, and keep the powder away from air and acids."
          },
          {
            "label": "Temperature",
            "line": "Avoid temperatures above 150 degC for powdered magnet material (SDS)."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 34,
    "unreachable": 1,
    "caveats": 4,
    "note": "Written by an AI assistant on 2026-10-26 from sources read in this run: Eclipse and Allstar SmCo datasheets, Arnold Recoma 35E datasheet, Allstar SmCo SDS, NASA NTRS 20130010718 (Bowman 2013), USGS MCS 2026 cobalt and rare-earth chapters, USGS 2025 critical-mineral page, EC critical raw materials page, PubChem samarium and cobalt records, and Wikipedia (composition only). The Naval Postgraduate School paper could not be opened. Eclipse and Allstar values are approximate, supplier reference values, not measured data. Producer shares and the 50% Curie-temperature figure are computed by this profile."
  },
  "sources": {
    "eclipse-smco": {
      "title": "Technical Data Sheet, Samarium Cobalt Magnets (SmCo)",
      "url": "https://www.eclipsemagnetics.com/site/assets/files/19544/eclipsemagnetics_smco_datasheet.pdf",
      "kind": "datasheet",
      "license": "manufacturer datasheet"
    },
    "allstar-smco-tech": {
      "title": "Samarium Cobalt Technical Data (ASM 09-23-2023)",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/09/Samarium-Cobalt-Technical-Data-ASM-09-23-2023.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "supplier datasheet"
    },
    "arnold-recoma35e": {
      "title": "Recoma 35E Sintered Samarium Cobalt Magnets (datasheet, Rev. 160204a)",
      "url": "https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Recoma-35E-160205-final.pdf",
      "year": 2016,
      "kind": "datasheet",
      "license": "manufacturer datasheet"
    },
    "allstar-smco-sds": {
      "title": "Safety Data Sheet, Samarium Cobalt (SDS SMC, Rev 1.0, 09 Feb 2024)",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Samarium-cobalt-SDS.pdf",
      "year": 2024,
      "kind": "datasheet",
      "license": "supplier document"
    },
    "bowman-2013": {
      "title": "Design Issues for Using Magnetic Materials in Radiation Environments at Elevated Temperature",
      "id": "NTRS 20130010718 (Nuclear and Emerging Technologies for Space 2013, paper 6801)",
      "url": "https://ntrs.nasa.gov/api/citations/20130010718/downloads/20130010718.pdf",
      "year": 2013,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "usgs-mcs2026-cobalt": {
      "title": "Mineral Commodity Summaries 2026, Cobalt",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-rare-earths": {
      "title": "Mineral Commodity Summaries 2026, Rare Earths",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-rare-earths.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit2025": {
      "title": "About the 2025 List of Critical Minerals (USGS)",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "ec-crm": {
      "title": "Critical raw materials (European Commission)",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "year": 2024,
      "kind": "web",
      "license": "European Commission web page"
    },
    "pubchem-samarium": {
      "title": "PubChem compound CID 23951, samarium: molecular weight and GHS classification",
      "id": "CID 23951",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23951",
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "pubchem-cobalt": {
      "title": "PubChem compound CID 104730, cobalt: molecular weight and GHS classification",
      "id": "CID 104730",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "wiki-smco": {
      "title": "Samarium-cobalt magnet (Wikipedia), composition and history sections only",
      "url": "https://en.wikipedia.org/wiki/Samarium%E2%80%93cobalt_magnet",
      "kind": "web",
      "license": "CC BY-SA"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/smco/"
}