{
  "spore": "profile",
  "id": "calcium-titanate",
  "spore_version": "0.2",
  "family": "oxide-ceramics",
  "name": "Calcium titanate",
  "abbreviation": "CaTiO3",
  "role": "perovskite oxide ceramic for microwave dielectrics and nuclear wasteforms",
  "category": "ceramics",
  "type": "oxides",
  "summary": "Calcium titanate (CaTiO3) is a perovskite oxide that also occurs as the mineral perovskite. A supplier safety data sheet describes a beige, insoluble powder with a melting point of 1975 °C and a density of 4.1 g/cc. A 2022 study of a sintered ceramic measured a relative permittivity of 145.97 and a Q times f of 4020 GHz, and a 2021 study of zirconolite wasteforms found that its perovskite phase was preferentially leached by strong acid.\n",
  "best_for": "Microwave dielectric resonator ceramics, usually in composites with a material that offsets its large temperature coefficient",
  "weakest_at": "Large positive temperature coefficient of resonant frequency (796.69 ppm/°C in the 2022 sintered ceramic), and preferential leaching of the perovskite phase in strong acid",
  "identity": {
    "formula": "CaTiO3",
    "cas": "12049-50-2",
    "crystal_system": "orthorhombic",
    "space_group": "Pnma",
    "designations": [],
    "source": "angstrom-sds",
    "where": "Angstrom Sciences SDS, Section 1 (CAS Number 12049-50-2, EC Number 234-988-1) and Section 9 (molecular weight 135.94 g/mol); space group Pnma from the high-pressure study arXiv 1006.4423; PubChem CID 162251 gives molecular formula CaO3Ti and molecular weight 135.94"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, powder (Angstrom Sciences SDS)",
      "value": 4.1,
      "bound": "exact",
      "unit": "g/cc",
      "scope": "material",
      "conditions": {
        "form": "powder, product as supplied (CAS 12049-50-2)",
        "temperature": "not stated on the sheet"
      },
      "method": "Value printed in a supplier safety data sheet, Section 9",
      "status": "ground",
      "source": "angstrom-sds",
      "where": "Section 9, Density row",
      "source_detail": {
        "title": "Angstrom Sciences: Safety Data Sheet, Calcium Titanium Oxide (CAS 12049-50-2)",
        "id": "Angstrom Sciences SDS, revised 07/08/15, EC 234-988-1",
        "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Calcium%20Titanium%20Oxide.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Theoretical density, sintered ceramic (Rietveld)",
      "value": 4.026,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2",
        "basis": "calculated from X-ray diffraction data by Rietveld refinement"
      },
      "method": "Theoretical density printed in Table 2 (as g cm-3) for the CT row; not a measured density",
      "status": "calculated",
      "source": "jmmm-cto2022",
      "where": "Table 2, rho theory column, CT row",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "density",
      "label": "Apparent density, sintered ceramic (Archimedes)",
      "value": 3.859,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2",
        "basis": "Archimedes immersion of the pellet"
      },
      "method": "Apparent density printed in Table 2 (as g cm-3) for the CT row, measured by the Archimedes method",
      "status": "ground",
      "source": "jmmm-cto2022",
      "where": "Table 2, rho apparent column, CT row",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "relative_density",
      "label": "Relative density, sintered ceramic",
      "value": 95.852,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2"
      },
      "method": "Ratio of apparent to theoretical density, printed in Table 2",
      "status": "ground",
      "note": "The abstract of the same study says the relative density is below 90 percent. That conflicts with Table 2, so the table value is kept and the conflict is noted in gaps.",
      "source": "jmmm-cto2022",
      "where": "Table 2, rho relative column, CT row",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, powder (Angstrom Sciences SDS)",
      "value": 1975,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "powder, product as supplied"
      },
      "method": "Value printed in a supplier safety data sheet, Section 9",
      "status": "ground",
      "source": "angstrom-sds",
      "where": "Section 9, Melting Point row",
      "source_detail": {
        "title": "Angstrom Sciences: Safety Data Sheet, Calcium Titanium Oxide (CAS 12049-50-2)",
        "id": "Angstrom Sciences SDS, revised 07/08/15, EC 234-988-1",
        "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Calcium%20Titanium%20Oxide.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "dielectric_constant",
      "label": "Relative permittivity, sintered ceramic (this work)",
      "value": 145.97,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2, solid-state route",
        "test": "Hakki-Coleman dielectric resonator method",
        "frequency": "not stated in the text",
        "processing": "precursors calcined at 1100 °C for 4 h, sintered at 1250 °C"
      },
      "method": "Value printed in Table 3 under 'This work' for the CT row, measured with the Hakki-Coleman dielectric resonator method",
      "status": "ground",
      "source": "jmmm-cto2022",
      "where": "Table 3, epsilon r column, CT row, This work",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "q_times_f",
      "label": "Quality factor times frequency, sintered ceramic (this work)",
      "value": 4020,
      "bound": "exact",
      "unit": "GHz",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2",
        "test": "Hakki-Coleman dielectric resonator method",
        "frequency": "not stated in the text"
      },
      "method": "Q times f value printed in Table 3 under 'This work' for the CT row",
      "status": "ground",
      "note": "q_times_f is not yet in spores/property-canon.yaml. It is a short snake_case name, as the brief allows.",
      "source": "jmmm-cto2022",
      "where": "Table 3, Q times f column, CT row, This work",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "tau_f",
      "label": "Temperature coefficient of resonant frequency, sintered ceramic (this work)",
      "value": 796.69,
      "bound": "exact",
      "unit": "ppm/°C",
      "scope": "material",
      "conditions": {
        "form": "ceramic sintered at 1250 °C from CaCO3 and TiO2",
        "test": "Hakki-Coleman dielectric resonator method"
      },
      "method": "Value printed as ppm/℃ in Table 3 under 'This work' for the CT row; calculated from resonant frequencies at two temperatures",
      "status": "ground",
      "note": "tau_f is not yet in spores/property-canon.yaml. It is a short snake_case name, as the brief allows.",
      "source": "jmmm-cto2022",
      "where": "Table 3, tau f column, CT row, This work",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "bulk_modulus",
      "label": "Bulk modulus K0, single crystal (equation-of-state fit)",
      "value": 181,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "single crystal, room temperature starting point",
        "pressure_range": "0 to 40 GPa",
        "k0_prime": "constrained to 4 in the fit"
      },
      "method": "Equation-of-state fit to X-ray pressure data (K0 printed as 181.0(6) GPa); the uncertainty in parentheses is in the last digit",
      "status": "ground",
      "uncertainty": "(6) in the last digit of 181.0",
      "source": "guennou2010",
      "where": "Section 3 (equation of state), Table II, K0 row, this work",
      "source_detail": {
        "title": "High-pressure investigations of CaTiO3 up to 60 GPa using X-ray diffraction and Raman spectroscopy",
        "id": "arXiv:1006.4423 (Guennou, Bouvier, Krikler, Kreisel, Haumont, Garbarino)",
        "url": "https://arxiv.org/pdf/1006.4423",
        "year": 2010,
        "kind": "paper",
        "license": "arXiv preprint, licence not checked"
      }
    },
    {
      "benchmark": "dielectric_constant",
      "label": "Relative permittivity, CaTiO3 from earlier work (ref 16, for comparison)",
      "value": 170,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "CaTiO3 ceramic from the earlier work cited as reference 16",
        "basis": "literature value listed in Table 3, not measured in the 2022 study"
      },
      "method": "Value printed in Table 3 on the second line of the CT row, under the reference column",
      "status": "ground",
      "source": "jmmm-cto2022",
      "where": "Table 3, epsilon r column, CT row, reference [16]",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "q_times_f",
      "label": "Quality factor times frequency, CaTiO3 from earlier work (ref 16, for comparison)",
      "value": 3600,
      "bound": "exact",
      "unit": "GHz",
      "scope": "material",
      "conditions": {
        "form": "CaTiO3 ceramic from the earlier work cited as reference 16",
        "basis": "literature value listed in Table 3, not measured in the 2022 study"
      },
      "method": "Q times f value printed in Table 3 on the second line of the CT row",
      "status": "ground",
      "note": "The introduction of the same study quotes Q times f of about 3,600 GHz for this reference, so the table and text agree here.",
      "source": "jmmm-cto2022",
      "where": "Table 3, Q times f column, CT row, reference [16]",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    },
    {
      "benchmark": "tau_f",
      "label": "Temperature coefficient of resonant frequency, CaTiO3 from earlier work (ref 16, for comparison)",
      "value": 800.12,
      "bound": "exact",
      "unit": "ppm/°C",
      "scope": "material",
      "conditions": {
        "form": "CaTiO3 ceramic from the earlier work cited as reference 16",
        "basis": "literature value listed in Table 3, not measured in the 2022 study"
      },
      "method": "Value printed as ppm/℃ in Table 3 on the second line of the CT row",
      "status": "ground",
      "note": "The introduction of the same study quotes about 1800 ppm/°C for this reference. Table 3 prints 800.12, which is used here, and the conflict is noted in gaps.",
      "source": "jmmm-cto2022",
      "where": "Table 3, tau f column, CT row, reference [16]",
      "source_detail": {
        "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
        "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
        "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
        "year": 2022,
        "kind": "paper",
        "license": "journal open access, licence not checked"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Strong acids at 90 °C, as a perovskite accessory phase in a zirconolite wasteform (1 M H2SO4 and 8 M HNO3)",
      "headline": "Acid leaching preferentially dissolves the calcium titanate perovskite phase; 2.6 wt.% remained after 1 M H2SO4 and 3.8 wt.% after 8 M HNO3.",
      "effect": "In a study of zirconolite nuclear wasteforms with an accessory perovskite phase (nominally Ce-bearing CaTiO3), the perovskite diffraction peak fell in every leaching medium, so the phase was preferentially leached. Sulfuric acid was the most effective, and after 8 M HNO3 about one-third of the original perovskite remained. The paper gives the dissolution reaction CaTiO3 + (6-x)H+ gives Ca2+ + Ti(OH)x(4-x)+ + (3-x)H2O, and it reports TiO2 precipitates on the surface.",
      "rating": "moderate",
      "conditions": {
        "basis": "accelerated static leaching of powders, 7 d per medium with 14 d cumulative, measured by X-ray diffraction after leaching",
        "temperature": "90 °C",
        "form": "zirconolite ceramic with accessory perovskite"
      },
      "source": "blackburn2021",
      "where": "Results (Table 1 phase fractions; perovskite peak after leaching); Discussion (reaction equation 1)"
    },
    {
      "environment": "Strong oxidizing agents",
      "headline": "The supplier sheet lists oxidizing agents as incompatible. No test or corrosion rate was found.",
      "effect": "The Angstrom Sciences sheet lists oxidizing agents as the reactivity hazard and asks for storage apart from listed incompatible conditions. The sheet gives no test or rate for calcium titanate with an oxidizer.",
      "rating": "unknown",
      "conditions": {
        "basis": "incompatibility statement in a supplier SDS; no test",
        "form": "powder"
      },
      "source": "angstrom-sds",
      "where": "Section 10 (Reactivity; Incompatible Conditions)"
    },
    {
      "environment": "Water and humidity",
      "headline": "The powder is insoluble in water according to the supplier. No humidity-ageing test was found.",
      "effect": "The Angstrom Sciences sheet gives water solubility as insoluble. No study of dielectric or mechanical change after humid storage was found in a source read in this run.",
      "rating": "unknown",
      "conditions": {
        "basis": "solubility statement only",
        "form": "powder"
      },
      "source": "angstrom-sds",
      "where": "Section 9 (Water Solubility)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem records the substance as not classified: 18 of 19 company reports say it does not meet GHS hazard criteria, and only 5.3 percent of companies gave GHS information.",
        "ghs": [],
        "source": "pubchem-cto",
        "where": "GHS Classification section (CID 162251)"
      },
      {
        "text": "The Angstrom Sciences sheet (revised 2015) gives no signal word and no hazard statements, and an HMIS health rating of 1. It says the powder may cause irritation to the eyes, skin, and on inhalation or ingestion, with no numeric toxicity value.",
        "ghs": [],
        "source": "angstrom-sds",
        "where": "Sections 2 and 11"
      }
    ],
    "failure_risks": [
      {
        "mode": "Preferential dissolution of the perovskite phase in strong acid",
        "trigger": "Acid leaching at 90 °C (1 M H2SO4 or 8 M HNO3) of a zirconolite wasteform that holds CaTiO3 as an accessory phase",
        "consequence": "Residual perovskite fell to 2.6 wt.% after 1 M H2SO4 and 3.8 wt.% after 8 M HNO3. The study says the perovskite phase is postulated to increase the release of plutonium to leachants, and that cerium release tracked the amount of perovskite present.",
        "severity": "high",
        "source": "blackburn2021",
        "where": "Introduction; Results (Table 1 and the perovskite peak after leaching); Discussion"
      },
      {
        "mode": "Large drift of the resonant frequency with temperature",
        "trigger": "Pure CaTiO3 used as a microwave resonator without a compensating partner phase",
        "consequence": "The sintered pure ceramic has a temperature coefficient of resonant frequency of 796.69 ppm/°C, so its resonant frequency moves strongly with temperature. The authors note that CaTiO3-based ceramics have mostly been used as one component of composites.",
        "severity": "moderate",
        "source": "jmmm-cto2022",
        "where": "Table 3 (CT row); Introduction"
      },
      {
        "mode": "Residual porosity in a sintered ceramic",
        "trigger": "Sintering at 1250 °C, the schedule used for the pure ceramic in the 2022 study",
        "consequence": "Table 2 gives a relative density of 95.852 percent, but the abstract says the relative density is below 90 percent. Porosity therefore needs to be measured for each batch before a dielectric value is relied on.",
        "severity": "low",
        "source": "jmmm-cto2022",
        "where": "Table 2; abstract"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Store in a cool, dry place in a tightly sealed container, apart from oxidizing agents and the other materials listed as incompatible.",
        "source": "angstrom-sds",
        "where": "Section 7 (Conditions for safe storage) and Section 10"
      },
      {
        "text": "Take care not to raise dust. Clean up spills with a HEPA filter vacuum into a closed container, and do not blow dust off clothing or skin with compressed air.",
        "source": "angstrom-sds",
        "where": "Section 6 (Accidental release measures) and Section 7 (Work/Hygienic Maintenance)"
      },
      {
        "text": "Wear safety glasses or goggles, rubber gloves and protective work clothing, as the sheet specifies.",
        "source": "angstrom-sds",
        "where": "Section 8 (Protective Gloves, Eye Protection, Body Protection)"
      }
    ],
    "mitigations": [
      {
        "text": "Provide sufficient ventilation to keep airborne concentrations at or below the threshold limit value. The sheet prints no numeric limit (N/A).",
        "source": "angstrom-sds",
        "where": "Section 7 (Ventilation) and Section 8 (Threshold Limit Value)"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Microwave dielectric resonator ceramic",
      "example": "A 2022 study measured a relative permittivity of 145.97 and a Q times f of 4020 GHz for a pure CaTiO3 sintered ceramic. Its introduction says CaTiO3-based ceramics have mostly been used as one component of composites, because of their moderate permittivity and positive temperature coefficient.",
      "source": "jmmm-cto2022",
      "where": "Introduction; Table 3, CT row"
    },
    {
      "application": "electronics-and-chips",
      "device": "Microwave absorber (reported application)",
      "example": "The 2022 study's introduction notes earlier work that showed CaTiO3 can be applied to microwave absorption in the X and Ku bands. Only the introduction states this, so it is a reported application, not a result of the study.",
      "source": "jmmm-cto2022",
      "where": "Introduction"
    }
  ],
  "supply": [
    {
      "subject": "Titanium (titanium sponge metal, 2025; the oxide feedstock of CaTiO3 is not covered by this source)",
      "producers": [
        {
          "country": "China",
          "share_percent": 70.3,
          "year": 2025
        },
        {
          "country": "Japan",
          "share_percent": 14.3,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 6.8,
          "year": 2025
        },
        {
          "country": "Kazakhstan",
          "share_percent": 4.3,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: consumption data for titanium scrap for the titanium metal industry were withheld in 2025, and scrap consumption data for the steel, superalloy and other industries were not available.",
      "substitutes": [
        "USGS: aluminum, nickel, specialty steels and zirconium alloys may be substituted for titanium where corrosion resistance is needed. This is a statement about metal uses, not oxide ceramics."
      ],
      "source": "usgs-mcs2026-titanium",
      "where": "World Sponge Metal Production table, 2025 column (world total 370,000 t; shares calculated by Space Mushroom against that total); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Angstrom Sciences safety data sheet: Calcium Titanium Oxide, CAS 12049-50-2 (revised 07/08/15)",
      "type": "sds",
      "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Calcium%20Titanium%20Oxide.pdf",
      "year": 2015
    },
    {
      "title": "PubChem: Calcium titanate (CID 162251), GHS classification summary",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/162251",
      "year": 2026
    },
    {
      "title": "NIST: Atomic Weights and Isotopic Compositions for All Elements",
      "type": "database",
      "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl"
    },
    {
      "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate (J. Met. Mater. Miner. 32(3), 2022)",
      "type": "paper",
      "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
      "year": 2022
    },
    {
      "title": "Influence of accessory phases and surrogate type on accelerated leaching of zirconolite wasteforms (npj Materials Degradation 5, 24)",
      "type": "paper",
      "url": "https://eprints.whiterose.ac.uk/173147/9/s41529-021-00171-8.pdf",
      "year": 2021
    },
    {
      "title": "High-pressure investigations of CaTiO3 up to 60 GPa using X-ray diffraction and Raman spectroscopy (arXiv:1006.4423)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/1006.4423",
      "year": 2010
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf",
      "year": 2026
    },
    {
      "title": "SurfaceNet: Strontium titanate (SrTiO3) datasheet",
      "type": "datasheet",
      "url": "https://surfacenet.de/files/kr_Strontium_Titanate.php"
    },
    {
      "title": "Stanford Advanced Materials: Material Safety Data Sheet, Strontium titanate (SrTiO3), version 2.0 (5 September 2012)",
      "type": "sds",
      "url": "https://www.sputtertargets.net/Public/pdf/strontium-titanate-msds.pdf",
      "year": 2012
    },
    {
      "title": "PubChem: Strontium titanium oxide (SrTiO3, CID 82899)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/82899",
      "year": 2026
    }
  ],
  "gaps": [
    "No thermal conductivity, thermal expansion, hardness or refractive index for calcium titanate was found in a source read in this run. No band gap was read either.",
    "The text does not state the measurement frequency for the pure CaTiO3 permittivity and Q times f values (Hakki-Coleman method, Table 3), so frequency is left out of the conditions.",
    "q_times_f and tau_f are not in spores/property-canon.yaml. They are short snake_case names, as the brief allows, and need adding to the canon.",
    "The 2022 study's introduction quotes about 1800 ppm/°C for reference 16, but Table 3 prints 800.12. The table value is kept.",
    "The 2022 study's abstract gives relative density below 90 percent, but Table 2 gives 95.852 percent. The table value is kept.",
    "No space, vacuum, outgassing, radiation or flight result for calcium titanate was found. Radiation tolerance of the Nd-doped ceramic was not read in a fetched source.",
    "No humidity-ageing or long-term water study for calcium titanate was found. The corrosion entries rest on the SDS reactivity statement and on the zirconolite leaching study, which tested the perovskite as an accessory phase rather than the pure compound.",
    "Calcium supply: no USGS chapter or other production source for calcium was read. The supply entry covers titanium as sponge metal, which is not the oxide feedstock of CaTiO3.",
    "Oxygen has no atomic weight here, because NIST prints an interval (15.99903 to 15.99977) rather than a single value. Atoms and atomic weight are given for calcium and titanium only.",
    "Critical-mineral status for titanium was not read: the USGS critical-minerals list was not opened in this run, so critical_lists is empty.",
    "The American Elements calcium titanate SDS page returned a bot challenge. A second supplier SDS that a search result described as classifying the material as hazardous under OSHA could not be opened, so the hazard entries rest on the Angstrom sheet and PubChem.",
    "Hazard data for the nanopowder form were not found. The classification refers to the bulk powder sheets read here.",
    "Strontium titanate (related section): the SurfaceNet page prints the loss tangent and thermal conductivity with garbled units, and its thermal expansion coefficient has no unit printed, so none of these are given. Band gap and refractive index were not read in a primary source. No electronic-device or space data were read for strontium titanate."
  ],
  "story": {
    "why": "Calcium titanate (CaTiO3) is a perovskite oxide, named after the mineral perovskite (Wikipedia credits the name to the Russian mineralogist Lev Perovski). Its structure is orthorhombic (space group Pnma), with tilted oxygen octahedra that lower the symmetry from the ideal cubic perovskite. The 2022 study measured a relative permittivity of 145.97 for a pure sintered ceramic. The 2021 nuclear study placed the same phase in SYNROC-type wasteforms, where it is a host for actinides but also the phase that is preferentially leached by strong acid. Its main limits are the large temperature coefficient of resonant frequency and that acid leaching.",
    "uses": [
      {
        "where": "Microwave dielectric resonators",
        "line": "The 2022 study measured a pure sintered CaTiO3 ceramic at a relative permittivity of 145.97 and a Q times f of 4020 GHz. Its introduction says CaTiO3 is mostly used as one component of microwave composites."
      },
      {
        "where": "Nuclear wasteforms (SYNROC-type ceramic)",
        "line": "The 2021 study notes that SYNROC-C, a wasteform for plutonium and other actinides, used zirconolite and perovskite as hosts. In its acid leach tests the perovskite phase was the one preferentially dissolved."
      }
    ],
    "can_do": [
      {
        "label": "Permittivity",
        "line": "A pure sintered ceramic measured 145.97 in the 2022 study. The same table lists 170 for CaTiO3 from earlier work.",
        "benchmark": "dielectric_constant",
        "scope": "material",
        "value": "145.97"
      },
      {
        "label": "Quality factor",
        "line": "The Q times f of the pure sintered ceramic is 4020 GHz at a frequency that the text does not state.",
        "benchmark": "q_times_f",
        "scope": "material",
        "value": "4020 GHz"
      },
      {
        "label": "Density",
        "line": "The Angstrom Sciences sheet gives a density of 4.1 g/cc for the powder. The sintered ceramic in the 2022 study had a theoretical density of 4.026 g/cm3.",
        "benchmark": "density",
        "scope": "material",
        "value": "4.1 g/cc"
      },
      {
        "label": "Melting point",
        "line": "The supplier sheet gives a melting point of 1975 °C for the powder.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "1975 °C"
      }
    ],
    "compare": "Calcium titanate is the lighter and lower-melting member of the perovskite family in this record. Its density is 4.1 g/cc and its melting point 1975 °C, against 5.12 g/cm3 and 2080 °C for strontium titanate in the related section. Its sintered permittivity of 145.97 is lower than the 300 that the strontium titanate datasheet quotes, although that datasheet prints no test conditions. Its large temperature coefficient of resonant frequency (796.69 ppm/°C) is the figure to check first when it is used in a resonator.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Permittivity",
        "benchmark": "dielectric_constant",
        "scope": "material"
      }
    ],
    "handling": [
      "Store dry and sealed, away from oxidizing agents.",
      "Avoid dust. Clean spills with a HEPA filter vacuum, and provide ventilation for dust-forming work.",
      "The sheet prints no numeric exposure limit (TLV N/A)."
    ],
    "good_for": [
      "Microwave resonators. The pure sintered ceramic has a relative permittivity of 145.97 and a Q times f of 4020 GHz.",
      "Nuclear wasteform research. CaTiO3 is one host phase in SYNROC-type ceramics that hold plutonium and other actinides."
    ],
    "watch_out": [
      "Temperature drift. The pure sintered ceramic has a temperature coefficient of resonant frequency of 796.69 ppm/°C, so it needs a compensating partner material.",
      "Acid durability. The perovskite phase was preferentially leached in 1 M H2SO4 and 8 M HNO3 at 90 °C.",
      "Patchy data. No thermal expansion, hardness or thermal conductivity value for calcium titanate was found in a source read in this run."
    ],
    "verdict": "Calcium titanate is a stable, high-melting perovskite with a useful microwave permittivity, but its temperature coefficient is large and its perovskite phase is the weak point under strong acid. The sources read here cover its phase data, microwave values and leaching behaviour. They give no thermal, mechanical or space data.",
    "recipe": {
      "line": "CaTiO3 is a calcium titanium oxide with the perovskite structure, with one calcium ion, one titanium ion and three oxygen per formula unit. In the 2022 study, the ceramic was made by solid-state reaction of CaCO3 with TiO2. The precursors were calcined at 1100 °C for 4 h, then pressed and sintered at 1250 °C.",
      "parts": [
        {
          "name": "Calcium",
          "symbol": "Ca",
          "role": "The large cation in the perovskite framework. In the 2022 study it came from calcium carbonate (CaCO3).",
          "atoms": 1,
          "atomic_weight": 40.078,
          "source": "nist-atomic-weights",
          "where": "Standard atomic weight column, Ca row (40.078(4))"
        },
        {
          "name": "Titanium",
          "symbol": "Ti",
          "role": "The small cation at the centre of each oxygen octahedron. In the 2022 study it came from TiO2.",
          "atoms": 1,
          "atomic_weight": 47.867,
          "source": "nist-atomic-weights",
          "where": "Standard atomic weight column, Ti row (47.867(1))"
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Three oxygen per formula unit, forming the tilted octahedral framework. NIST prints an interval for oxygen rather than one value, so no weight is given here.",
          "source": "jmmm-cto2022",
          "where": "Materials and methods (precursors); formula CaO3Ti from PubChem CID 162251"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The supplier sheet and PubChem give no hazard classification for calcium titanate. The sheet lists only possible irritation.",
        "points": [
          {
            "label": "The powder",
            "line": "The Angstrom Sciences sheet gives no signal word and no hazard statements. PubChem reports that 18 of 19 company reports do not meet GHS criteria."
          },
          {
            "label": "Irritation",
            "line": "The sheet says the powder may irritate the eyes and skin, and may irritate if inhaled or swallowed. It gives no numeric toxicity value."
          },
          {
            "label": "Dust",
            "line": "Avoid raising dust. The sheet advises a HEPA filter vacuum for spills."
          }
        ],
        "level": 0,
        "verdict": "No hazard classification found"
      },
      {
        "title": "If it fails",
        "lead": "These results come from leaching tests and resonator measurements, not from service incidents.",
        "points": [
          {
            "label": "Acid",
            "line": "In strong acid at 90 °C the perovskite phase of a zirconolite wasteform was preferentially dissolved. After 1 M H2SO4 it kept 2.6 wt.% and after 8 M HNO3 it kept 3.8 wt.%."
          },
          {
            "label": "Temperature",
            "line": "The pure sintered ceramic has a temperature coefficient of resonant frequency of 796.69 ppm/°C, so resonant frequency moves strongly with temperature."
          },
          {
            "label": "Porosity",
            "line": "Table 2 gives a relative density of 95.852 percent, but the abstract says below 90 percent. Measure porosity for each batch."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Keep it dry and closed",
            "line": "Store in a cool, dry place in a tightly sealed container, away from oxidizing agents."
          },
          {
            "label": "Avoid dust",
            "line": "Do not raise dust. Clean spills with a HEPA filter vacuum into a closed container, and do not blow dust off clothing with compressed air."
          },
          {
            "label": "Ventilation",
            "line": "Provide enough ventilation to keep the air at or below the threshold limit value. The sheet prints no numeric limit."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 12,
    "unreachable": 2,
    "caveats": 3,
    "note": "Read by an AI assistant on 2026-10-26 from the pages and PDFs fetched in that run. Unreachable in that run: the American Elements calcium titanate SDS (bot challenge) and a Santa Cruz SDS (served as HTML, not a PDF). Caveats: the 2022 abstract and Table 2 disagree on relative density, the 2022 introduction and Table 3 disagree on the reference 16 tau f, and Table 3 gives no measurement frequency. The strontium titanate values are in the related block and are not in the properties list."
  },
  "sources": {
    "angstrom-sds": {
      "title": "Angstrom Sciences: Safety Data Sheet, Calcium Titanium Oxide (CAS 12049-50-2)",
      "id": "Angstrom Sciences SDS, revised 07/08/15, EC 234-988-1",
      "url": "https://angstromsciences.com/wp-content/uploads/files/SDS/Calcium%20Titanium%20Oxide.pdf",
      "year": 2015,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "pubchem-cto": {
      "title": "PubChem compound record, Calcium titanate (CID 162251)",
      "id": "CID 162251; molecular formula CaO3Ti; molecular weight 135.94",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/162251",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "nist-atomic-weights": {
      "title": "NIST: Atomic Weights and Isotopic Compositions for All Elements",
      "id": "NIST Physical Measurement Laboratory, standard atomic weight column",
      "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl",
      "kind": "database",
      "license": "US government work"
    },
    "jmmm-cto2022": {
      "title": "Effect of A-site modification on structural and microwave dielectric properties of calcium titanate",
      "id": "J. Met. Mater. Miner. 32(3), 118-125 (2022), DOI 10.55713/jmmm.v32i3.1525",
      "url": "https://jmmm.material.chula.ac.th/index.php/jmmm/article/download/1525/1165",
      "year": 2022,
      "kind": "paper",
      "license": "journal open access, licence not checked"
    },
    "blackburn2021": {
      "title": "Influence of accessory phases and surrogate type on accelerated leaching of zirconolite wasteforms",
      "id": "doi:10.1038/s41529-021-00171-8 (npj Materials Degradation 5, 24)",
      "url": "https://eprints.whiterose.ac.uk/173147/9/s41529-021-00171-8.pdf",
      "year": 2021,
      "kind": "paper",
      "license": "CC BY 4.0 (repository copy)"
    },
    "guennou2010": {
      "title": "High-pressure investigations of CaTiO3 up to 60 GPa using X-ray diffraction and Raman spectroscopy",
      "id": "arXiv:1006.4423 (Guennou, Bouvier, Krikler, Kreisel, Haumont, Garbarino)",
      "url": "https://arxiv.org/pdf/1006.4423",
      "year": 2010,
      "kind": "paper",
      "license": "arXiv preprint, licence not checked"
    },
    "usgs-mcs2026-titanium": {
      "title": "Mineral Commodity Summaries 2026, Titanium and Titanium Dioxide",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "sto-surfacenet": {
      "title": "SurfaceNet: Strontium titanate (SrTiO3) datasheet",
      "id": "SurfaceNet datasheet, strontium titanate",
      "url": "https://surfacenet.de/files/kr_Strontium_Titanate.php",
      "kind": "web",
      "license": "supplier page, linked not reproduced"
    },
    "sam-sto-msds": {
      "title": "Stanford Advanced Materials: Material Safety Data Sheet, Strontium titanate (SrTiO3)",
      "id": "SAM strontium titanate MSDS, version 2.0, 5 September 2012, CAS 12060-59-2",
      "url": "https://www.sputtertargets.net/Public/pdf/strontium-titanate-msds.pdf",
      "year": 2012,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "pubchem-sto": {
      "title": "PubChem compound record, Strontium titanium oxide (SrTiO3, CID 82899)",
      "id": "CID 82899; molecular formula O3SrTi; molecular weight 183.49",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/82899",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "wikipedia-cto": {
      "title": "Wikipedia: Calcium titanate (used for the history of the name only)",
      "id": "English Wikipedia article, Calcium titanate",
      "url": "https://en.wikipedia.org/wiki/Calcium_titanate",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/calcium-titanate/"
}