{ "spore": "profile", "id": "neodymium", "spore_version": "0.2", "family": "rare-earth-metals", "name": "Neodymium", "abbreviation": "Nd", "role": "magnet alloy feedstock and solid-state laser dopant", "category": "metals", "type": "heavy-metals", "summary": "Neodymium is the element Nd (atomic number 60), a silvery-white lanthanide metal with a density of 7.007 g/cm3 at 20 °C and a melting point of 1022 °C in the Wikipedia infobox. It is one of the rare-earth elements and occurs in minerals with the others. The metal is made by electrolysis of neodymium oxide in a molten fluoride salt. Its main uses are as the magnet element in Nd-Fe-B permanent magnets and as the active ion in Nd:YAG and neodymium-glass lasers. The Mars Orbiter Laser Altimeter flew a diode-pumped Nd:YAG transmitter on Mars Global Surveyor, launched on 5 November 1996. The metal tarnishes in air and reacts with water, and its fine chips and powder are flammable, so it needs dry, inert handling.\n", "best_for": "Magnet-grade and laser-grade neodymium, where a 1064 nm Nd:YAG laser or a Nd-Fe-B magnet is the goal (Wikipedia, NASA MOLA paper)", "weakest_at": "Tarnishes in air, reacts with water and releases hydrogen with acids, and fine chips and powder are flammable (Wikipedia, Lesker MSDS)", "identity": { "formula": "Nd (element, atomic number 60); unalloyed metal, sold by Goodfellow as pellets and foil", "cas": "7440-00-8", "designations": [], "source": "pubchem-nd", "where": "Names and Identifiers, CAS entry (PubChem CID 23934); EC number 231-109-3 is printed in the PubChem Regulatory Information, REACH entry" }, "tags": { "environments": [], "stresses": [], "applications": [ "optics-and-cameras", "mechanisms" ] }, "properties": [ { "benchmark": "density", "label": "Density, neodymium (Wikipedia infobox, 20 °C)", "value": 7.007, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "temperature": "20 °C", "unit_in_source": "7.007 g/cm3" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Density (at 20 °C) 7.007 g/cm3", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, neodymium (PubChem experimental property, 25 °C)", "value": 7.01, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "temperature": "25 °C" }, "method": "Experimental value listed in the PubChem record", "status": "ground", "source": "pubchem-nd", "where": "Chemical and Physical Properties, Experimental Properties, Density (7.01 at 25 °C)", "source_detail": { "title": "PubChem compound record: Neodymium (CID 23934), including ECHA C and L Inventory classification", "id": "CID 23934; CAS 7440-00-8; EC 231-109-3", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23934/JSON", "year": 2026, "kind": "database", "license": "PubChem (NCBI), public domain; sections attributed to ECHA and others" } }, { "benchmark": "density", "label": "Density, neodymium pellets (Goodfellow, 20 °C)", "value": 7.004, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "temperature": "20 °C", "purity": "not stated on the page" }, "method": "Typical value printed in a supplier product datasheet", "status": "ground", "source": "goodfellow-nd-pellets", "where": "Physical Properties table, row Density (7.004@20 °C)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, solid neodymium (WebElements)", "value": 6800, "bound": "exact", "unit": "kg/m3", "scope": "material", "conditions": { "state": "solid", "unit_in_source": "6800 kg m-3" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "note": "WebElements prints 6800 kg/m3 (6.8 g/cm3), about 3 % below the 7.0 g/cm3 values from the other three sources. The page does not say why.", "source": "webelements-nd", "where": "Density properties, row Density of solid (6800 kg m-3)", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point, neodymium (Wikipedia infobox)", "value": 1022, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "not stated", "unit_in_source": "1295 K (1022 °C, 1872 °F)" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "note": "The Wikipedia text gives approximately 1024 °C, while its infobox gives 1022 °C. The infobox value is used here.", "source": "wikipedia-nd", "where": "Infobox, row Melting point, 1295 K (1022 °C, 1872 °F)", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, neodymium pellets (Goodfellow)", "value": 1021, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "not stated" }, "method": "Value printed in a supplier product datasheet", "status": "ground", "source": "goodfellow-nd-pellets", "where": "Thermal Properties table, row Melting point (1021)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "boiling_point", "label": "Boiling point, neodymium (Wikipedia infobox)", "value": 3074, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "not stated", "unit_in_source": "3347 K (3074 °C, 5565 °F)" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Boiling point, 3347 K (3074 °C, 5565 °F)", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "boiling_point", "label": "Boiling point, neodymium pellets (Goodfellow)", "value": 3068, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "not stated" }, "method": "Value printed in a supplier product datasheet", "status": "ground", "note": "Goodfellow prints 3068 °C and Wikipedia prints 3074 °C. Both are entered and the difference is kept.", "source": "goodfellow-nd-pellets", "where": "Physical Properties table, row Boiling point (3068)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "specific_heat", "label": "Specific heat capacity, neodymium (Wikipedia infobox)", "value": 190.308, "bound": "exact", "unit": "J/(kg·K)", "scope": "material", "conditions": { "temperature": "not stated in the infobox" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "note": "The infobox gives no temperature. The Goodfellow pellets value is about 8 % higher at 25 °C, and both are entered.", "source": "wikipedia-nd", "where": "Infobox, row Specific heat capacity 190.308 J/(kg·K)", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "specific_heat", "label": "Specific heat capacity, neodymium pellets (Goodfellow, 25 °C)", "value": 205, "bound": "exact", "unit": "J/(kg·K)", "scope": "material", "conditions": { "temperature": "25 °C" }, "method": "Typical value printed in a supplier product datasheet", "status": "ground", "source": "goodfellow-nd-pellets", "where": "Thermal Properties table, row Specific heat (205@25 °C)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, neodymium (Wikipedia infobox)", "value": 16.5, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "temperature": "not stated in the infobox", "unit_in_source": "16.5 W/(m⋅K)" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Thermal conductivity 16.5 W/(m⋅K)", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, neodymium (WebElements)", "value": 17, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "temperature": "not stated" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "source": "webelements-nd", "where": "Heat and conduction, row Thermal conductivity (17 W m-1 K-1)", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, neodymium pellets (Goodfellow, 0 to 100 °C)", "value": 13, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "temperature": "0 to 100 °C" }, "method": "Typical value printed in a supplier product datasheet", "status": "ground", "note": "Goodfellow prints 13 W/(m·K) and Wikipedia prints 16.5 W/(m·K). The gap between sources is about 25 %, so the values are kept with their conditions.", "source": "goodfellow-nd-pellets", "where": "Thermal Properties table, row Thermal conductivity (13@0-100 °C)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, neodymium (Wikipedia infobox, 20 °C)", "value": 6.7, "bound": "exact", "unit": "ppm/K", "scope": "material", "conditions": { "temperature": "20 °C", "unit_in_source": "6.7 x 10-6 per K", "crystal_form": "double hexagonal close-packed, averaged over axes (alpha_average = alpha_V/3)" }, "method": "Value printed in the Wikipedia infobox and footnote; the footnote gives the a-axis value as 4.8 and the c-axis value as 10.5 (x10-6/K) at 20 °C", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Thermal expansion 6.7 x 10-6 /K (at 20 °C); footnote a", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, neodymium pellets (Goodfellow, 0 to 100 °C)", "value": 6.7, "bound": "exact", "unit": "ppm/K", "scope": "material", "conditions": { "temperature": "0 to 100 °C" }, "method": "Typical value printed in a supplier product datasheet", "status": "ground", "source": "goodfellow-nd-pellets", "where": "Thermal Properties table, row Coefficient of thermal expansion (6.7@0-100 °C)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, neodymium (WebElements)", "value": 9.6, "bound": "exact", "unit": "ppm/K", "scope": "material", "conditions": { "temperature": "not stated", "unit_in_source": "9.6 x 10-6 K-1" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "note": "WebElements prints 9.6 x 10-6 K-1, while Wikipedia and Goodfellow both print 6.7. The two values are entered with their sources and not averaged.", "source": "webelements-nd", "where": "Heat and conduction, row Coefficient of linear thermal expansion (9.6 x 10-6 K-1)", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "elastic_modulus", "label": "Young's modulus, neodymium (Wikipedia infobox)", "value": 41.4, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated in the infobox" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Young's modulus 41.4 GPa", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "elastic_modulus", "label": "Young's modulus, neodymium (WebElements)", "value": 41, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "source": "webelements-nd", "where": "Elastic properties, row Young's modulus 41 GPa", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "shear_modulus", "label": "Shear modulus (rigidity), neodymium (Wikipedia infobox)", "value": 16.3, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated in the infobox" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Shear modulus 16.3 GPa", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "shear_modulus", "label": "Rigidity modulus, neodymium (WebElements)", "value": 16, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "source": "webelements-nd", "where": "Elastic properties, row Rigidity modulus 16 GPa", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "bulk_modulus", "label": "Bulk modulus, neodymium (Wikipedia infobox)", "value": 31.8, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated in the infobox" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "note": "The Wikipedia text gives approximately 33 GPa from ultrasonic measurements, which differs from the infobox. The infobox value is used.", "source": "wikipedia-nd", "where": "Infobox, row Bulk modulus 31.8 GPa", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "bulk_modulus", "label": "Bulk modulus, neodymium (WebElements)", "value": 32, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temperature": "not stated" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "source": "webelements-nd", "where": "Elastic properties, row Bulk modulus 32 GPa", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "poissons_ratio", "label": "Poisson's ratio, neodymium (Wikipedia infobox)", "value": 0.281, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "temperature": "not stated in the infobox" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Poisson ratio 0.281", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "poissons_ratio", "label": "Poisson's ratio, neodymium (WebElements)", "value": 0.28, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "temperature": "not stated" }, "method": "Value printed on the WebElements physical-properties page", "status": "ground", "source": "webelements-nd", "where": "Elastic properties, row Poisson's ratio 0.28 (no units)", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "vickers_hardness", "label": "Vickers hardness range, neodymium (Wikipedia infobox)", "value": 345, "value_high": 745, "bound": "range", "unit": "MPa", "scope": "material", "conditions": { "temperature": "not stated in the infobox", "note_on_range": "the infobox gives a range, not a single test value" }, "method": "Range printed in the Wikipedia infobox", "status": "ground", "note": "No canonical name exists for hardness, so vickers_hardness is a new name and is listed in gaps. The range is given by Wikipedia without test conditions.", "source": "wikipedia-nd", "where": "Infobox, row Vickers hardness 345-745 MPa", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "vickers_hardness", "label": "Vickers hardness, neodymium (WebElements)", "value": 343, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "temperature": "not stated", "unit_in_source": "343 MN m-2" }, "method": "Value printed on the WebElements physical-properties page, given as MN m-2 (equal to MPa)", "status": "ground", "note": "No canonical name exists for hardness, so vickers_hardness is a new name and is listed in gaps.", "source": "webelements-nd", "where": "Hardnesses, row Vickers hardness 343 MN m-2", "source_detail": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity, neodymium polycrystalline (Wikipedia infobox)", "value": 643, "bound": "exact", "unit": "nΩ·m", "scope": "material", "conditions": { "temperature": "not stated in the infobox", "form": "polycrystalline" }, "method": "Value printed in the Wikipedia infobox", "status": "ground", "source": "wikipedia-nd", "where": "Infobox, row Electrical resistivity, poly 643 nΩ⋅m", "source_detail": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity, neodymium pellets (Goodfellow, 20 °C)", "value": 64, "bound": "exact", "unit": "µOhm·cm", "scope": "material", "conditions": { "temperature": "20 °C", "unit_in_source": "µOhmcm" }, "method": "Typical value printed in a supplier product datasheet", "status": "ground", "note": "The Goodfellow value of 64 µOhm·cm equals 640 nΩ·m, which agrees with the Wikipedia value of 643 nΩ·m to within about 0.5 %.", "source": "goodfellow-nd-pellets", "where": "Electrical Properties table, row Electrical resistivity (64@20 °C)", "source_detail": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" } } ], "corrosion": [ { "environment": "Dry or moist air at room temperature", "headline": "The metal tarnishes in air, and its surface oxide can flake away and expose fresh metal.", "effect": "Wikipedia says the metal tarnishes in air and that its surface oxide can flake away, exposing fresh metal and letting oxidation continue. The Lesker MSDS says the metal may react with air and atmospheric moisture and may spontaneously catch fire, and it advises avoiding damp conditions.", "rating": "moderate", "conditions": { "atmosphere": "air and atmospheric moisture", "temperature": "room temperature" }, "source": "wikipedia-nd", "where": "Chemical properties section, first paragraph on air; Lesker MSDS Section V" }, { "environment": "Air above about 150 °C", "headline": "Neodymium oxidises rapidly in air above about 150 °C, so processing needs argon or vacuum.", "effect": "The Goodfellow page says neodymium oxidises rapidly in air above about 150 °C, and that all processing requires argon or vacuum. No rate figure is given on the page.", "rating": "severe", "conditions": { "temperature": "above about 150 °C", "atmosphere": "air" }, "source": "goodfellow-nd-general", "where": "Property table, Melting Point row note" }, { "environment": "Water", "headline": "Neodymium reacts with water, more slowly in cold water and faster in hot water.", "effect": "Wikipedia says neodymium is electropositive and reacts with water to give neodymium(III) hydroxide and hydrogen, slowly in cold water and faster in hot water.", "rating": "moderate", "conditions": { "temperature": "cold and hot water", "form": "metal" }, "source": "wikipedia-nd", "where": "Chemical properties section, paragraph on water" }, { "environment": "Strong acids", "headline": "Contact with strong acids releases hydrogen from the metal.", "effect": "The Lesker MSDS says contact with strong acids may cause the evolution of hydrogen. PubChem records the metal as soluble in dilute acids, and Wikipedia says neodymium hydroxide dissolves in hydrochloric acid.", "rating": "severe", "conditions": { "acid": "strong acids, not named", "temperature": "not stated" }, "source": "lesker-nd-msds", "where": "Section VII Reactivity Data, Hazardous Decomposition Products" } ], "risks": { "hazards": [ { "text": "PubChem GHS summary for neodymium (ECHA C and L notifications, 463 company reports): H228 flammable solid in 34.3 %, H251 self-heating in 33.3 %, H315 skin irritation and H319 eye irritation in 41.9 %, H413 in 10.6 %, with signal word Danger. 261 of 463 reports say the substance does not meet GHS criteria.", "ghs": [ "H228", "H251", "H315", "H319", "H413" ], "source": "pubchem-nd", "where": "Safety and Hazards, Hazards Identification, GHS Classification" }, { "text": "Wikipedia says that finely divided neodymium metal is flammable and can undergo self-heating sufficient to cause ignition, and that the powder can irritate the skin and eyes.", "ghs": [], "source": "wikipedia-nd", "where": "Health and safety paragraph, on finely divided metal" }, { "text": "The Kurt J. Lesker neodymium MSDS (last revised 8/13/96) lists the metal as a DOT Flammable Solid and says that grinding or cutting may form an explosive dust-air mixture.", "ghs": [], "source": "lesker-nd-msds", "where": "Section IV Unusual Fire and Explosion Hazards; Section IX Transportation Requirements" }, { "text": "The Goodfellow page says neodymium chips and turnings are flammable and need inert-atmosphere handling.", "ghs": [], "source": "goodfellow-nd-general", "where": "Mechanical properties table, Hardness row note" } ], "failure_risks": [ { "mode": "Fire in fines, chips and turnings", "trigger": "Finely divided metal, turnings or dust exposed to air or moisture, or produced by grinding or cutting", "consequence": "The metal can self-heat enough to ignite, and the Lesker sheet says it may spontaneously catch fire in air or moisture. Grinding may form an explosive dust-air mixture.", "severity": "high", "source": "lesker-nd-msds", "where": "Section IV Unusual Fire and Explosion Hazards; Section V Steps to be taken in case of spill" }, { "mode": "Oxide spalling and continued oxidation", "trigger": "Exposure to air, with the surface oxide flaking away", "consequence": "The loose oxide exposes fresh metal, so oxidation continues and the metal keeps tarnishing.", "severity": "moderate", "source": "wikipedia-nd", "where": "Chemical properties section, paragraph on air" }, { "mode": "Hydrogen release on contact with water or strong acid", "trigger": "Contact with water (slow in cold water, faster in hot water) or with strong acids", "consequence": "Neodymium hydroxide forms and hydrogen gas is released, which is flammable. The Lesker sheet also says strong acids may cause the evolution of hydrogen.", "severity": "high", "source": "wikipedia-nd", "where": "Chemical properties section, paragraph on water; Lesker Section VII" } ], "side_effects": [ { "text": "The Lesker MSDS says that dust irritates the nose and throat, and that repeated exposure above the recommended limits over a long period can lead to dust in the lungs and, in time, scarring. Section II prints a limit of 15 mg/m3 for neodymium, but the column is not clear in the PDF text.", "affects": "Workers who grind, cut or handle the metal in dust form", "source": "lesker-nd-msds", "where": "Section VI Effects of Overexposure, Inhalation; Section II Hazardous Ingredients" } ], "handling": [ { "text": "Keep the metal dry and avoid contact with air and moisture. Store it under light mineral oil or take other steps to slow spontaneous oxidation, and use a dry inert atmosphere for machining or handling powder (Lesker MSDS).", "source": "lesker-nd-msds", "where": "Section IX Precautions to be Taken in Handling and Storing" }, { "text": "Keep the metal away from oxidizing agents, and do not agitate the fine powder in air (Lesker MSDS).", "source": "lesker-nd-msds", "where": "Section IX Precautions to be Taken in Handling and Storing" }, { "text": "Do not use water or CO2 extinguishers on a neodymium fire. Smother it with dry sand or a dry powder agent made for metal fires (Lesker MSDS).", "source": "lesker-nd-msds", "where": "Section IV Special Fire Fighting Procedures" }, { "text": "Use local exhaust ventilation, or explosion-proof exhaust where needed, and a NIOSH-approved dust respirator if airborne levels exceed the limits (Lesker MSDS).", "source": "lesker-nd-msds", "where": "Section VIII Respiratory Protection and Ventilation" } ], "mitigations": [] }, "uses": [ { "application": "optics-and-cameras", "device": "Nd:YAG laser altimeter transmitter on Mars Global Surveyor (MOLA, launched 5 November 1996)", "example": "The MOLA transmitter is a diode-pumped Nd:YAG laser at 1.064 µm. Its Table 1 gives an actual pulse energy of 49 mJ and a pulse width of 8.4 ns at 10 Hz, against a specification of 40 mJ and 10 ns. The neodymium enters the laser as the dopant in the garnet crystal, and the metal is the precursor for crystal growth as the oxide (Goodfellow).", "source": "mola-nasa-2000", "where": "Mars Orbiter Laser Altimeter: Laser Transmitter section; Table 1, Specifications and Actual rows" }, { "application": "optics-and-cameras", "device": "Neodymium-glass laser amplifiers at the National Ignition Facility", "example": "Wikipedia says flashlamps excite neodymium ions in phosphate-glass slabs at the National Ignition Facility, which amplify infrared pulses at about 1053 nm. The facility's frequency-tripled output is at 351 nm.", "source": "wikipedia-nd", "where": "Lasers section, paragraph on the National Ignition Facility" }, { "application": "mechanisms", "device": "Nd-Fe-B permanent magnets for electric motors and generators, with neodymium as the magnet element", "example": "Wikipedia says the larger applications include electric motors in industrial equipment, robots and electric vehicles, and that Nd-Fe-B magnets are also used in the generators of some wind turbines. The metal is the feedstock for the magnet alloy, not the magnet itself.", "source": "wikipedia-nd", "where": "Magnets section, paragraphs on motors and wind turbines" } ], "supply": [ { "subject": "Rare earths (neodymium is not reported separately by USGS)", "abundance": "41 mg/kg in the Earth's crust (Wikipedia, citing the CRC Handbook)", "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": [], "recycling": "USGS: limited quantities of rare earths were recovered from batteries, permanent magnets and fluorescent lamps. Wikipedia adds that direct recycling can preserve the magnet alloy for remelting.", "substitutes": [ "USGS: substitutes are available for many applications but generally are less effective." ], "source": "usgs-ree-2026", "where": "World Mine Production table, 2025 (world total 390,000 t; shares calculated by Space Mushroom from China 270,000, United States 51,000, Australia 29,000 and Burma 22,000). Reserves: China 44,000,000 t of more than 75,000,000 t world total. Recycling and Substitutes sections. Abundance: Wikipedia Occurrence section." }, { "subject": "Rare-earth compounds and metals imported into the United States", "producers": [ { "country": "China", "share_percent": 71, "year": 2024 }, { "country": "Malaysia", "share_percent": 13, "year": 2024 }, { "country": "Japan", "share_percent": 5, "year": 2024 }, { "country": "Estonia", "share_percent": 5, "year": 2024 } ], "critical_lists": [], "recycling": "", "substitutes": [], "source": "usgs-ree-2026", "where": "Import Sources (2021-24) paragraph; the year column shows the end of the 2021 to 2024 range. Net import reliance for compounds and metals in 2025e is 67 %, from the Salient Statistics table." }, { "subject": "Neodymium oxide price, 99.5 % minimum", "producers": [], "critical_lists": [], "recycling": "", "substitutes": [], "source": "usgs-ree-2026", "where": "Salient Statistics, price row Neodymium oxide, 99.5% minimum: 73 dollars per kg in 2025e (56 in 2024)" }, { "subject": "China export controls, April 2025", "producers": [], "critical_lists": [], "recycling": "", "substitutes": [], "source": "usgs-ree-2026", "where": "Events, Trends, and Issues: the April 2025 controls named samarium, gadolinium, terbium, dysprosium, lutetium, scandium and yttrium. Neodymium is not in that list in the USGS text." } ], "media": [], "documents": [ { "title": "Wikipedia: Neodymium", "type": "database", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026 }, { "title": "PubChem compound record for neodymium (CID 23934), including ECHA C and L classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23934", "year": 2026 }, { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "type": "database", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "year": 2026 }, { "title": "Goodfellow neodymium pellets, physical and thermal properties (product datasheet)", "type": "datasheet", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group" }, { "title": "Goodfellow rare-earth metals page: neodymium (general properties and applications)", "type": "datasheet", "url": "https://www.goodfellow.com/usa/material/rare-earth-metals/neodymium" }, { "title": "NIST: Atomic Weights and Isotopic Compositions for Neodymium", "type": "database", "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Nd&all=all" }, { "title": "Kurt J. Lesker Company material safety data sheet: Neodymium (last revised 8/13/96)", "type": "sds", "url": "https://www.lesker.com/newweb/deposition_materials/pdf/msds_nd.pdf", "year": 1996 }, { "title": "Mineral Commodity Summaries 2026: Rare Earths (USGS)", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-rare-earths.pdf", "year": 2026 }, { "title": "Space Operation of the MOLA laser (Afzal, NASA Goddard, 2000 conference paper)", "type": "paper", "url": "https://ntrs.nasa.gov/api/citations/20000053090/downloads/20000053090.pdf", "year": 2000 } ], "gaps": [ "Critical-mineral listing: the USGS 2025 critical minerals list and the EU critical raw materials list (Regulation (EU) 2024/1252) could not be opened in this run (the USGS page returned a short error page and the EUR-Lex page returned nothing), so critical_lists is empty.", "Neodymium-specific production: USGS reports rare earths as one group, so the producer shares above are for all rare earths, not for neodymium alone.", "Mechanical strength: no tensile or yield datasheet value for neodymium was read in this run. The Goodfellow page gives only an approximate tensile strength of about 200 MPa, which is not entered.", "Vickers hardness is entered under the new name vickers_hardness because the property file has no canonical name for it. Hardness is printed in MPa by WebElements and as a range by Wikipedia.", "The Wikipedia infobox gives an antiferromagnetic transition below 20 K, and WebElements prints a sound speed of 2330 m/s. Neither has a canonical property name, so neither is entered.", "Flight environment: the MOLA laser flew in orbit around Mars, but no environment tag in the allowed list fits Mars orbit, so tags.environments is empty. No vacuum, radiation or thermal-cycling test on the metal itself was found.", "Corrosion data are qualitative. No measured oxidation rate or weight-gain figure for neodymium in air or water was found in an opened source.", "Hazard data rest on a 1996 Lesker sheet (no GHS statements), the PubChem notification summary and the Wikipedia text. No current supplier safety data sheet for the metal was opened in this run, so the most recent classification is not confirmed.", "Density and thermal values disagree between sources (density 6.8 to 7.01 g/cm3, thermal conductivity 13 to 17 W/(m·K), expansion 6.7 and 9.6 ppm/K). Each value is entered with its own source and conditions, and none is averaged.", "Media: the lithium profile has an images section. No images for neodymium were read in this run, so no media section is included.", "Recipe: production is given as electrolysis of the oxide (Wikipedia) and calcium reduction of the fluoride (Goodfellow). The process conditions for the industrial route were not read in full." ], "story": { "why": "Neodymium is a rare-earth metal whose uses come from its 4f electrons. It is the magnet element in Nd-Fe-B permanent magnets, the strongest class of magnet in common use, and it is the active ion in Nd:YAG and neodymium-glass lasers. The Nd:YAG line at 1064 nm is the one that a 1996 Mars orbiter used for laser altimetry. The metal itself is not a structural material. Its value to a spacecraft comes from the laser and magnet applications, not from the bare metal.", "uses": [ { "where": "Laser altimetry in orbit around Mars", "line": "The Mars Orbiter Laser Altimeter on Mars Global Surveyor, launched on 5 November 1996, used a diode-pumped Nd:YAG transmitter at 1.064 µm. The NASA paper reports 49 mJ actual pulse energy at 10 Hz, against a specification of 40 mJ." }, { "where": "Neodymium-glass lasers", "line": "Wikipedia says that flashlamps excite neodymium ions in phosphate-glass slabs at the National Ignition Facility, which amplify infrared pulses at about 1053 nm." }, { "where": "Permanent magnets in motors and generators", "line": "Wikipedia says that Nd-Fe-B magnets are used in electric motors for industrial equipment, robots and electric vehicles, and in the generators of some wind turbines. Neodymium is the feedstock for the magnet alloy." } ], "can_do": [ { "label": "Weight", "line": "Density is 7.007 g/cm3 at 20 °C in the Wikipedia infobox, and 7.004 g/cm3 at 20 °C for Goodfellow pellets.", "benchmark": "density", "scope": "material", "value": "7.007 g/cm3" }, { "label": "Melting", "line": "Melting point is 1022 °C in the Wikipedia infobox, and 1021 °C for Goodfellow pellets.", "benchmark": "melting_point", "scope": "material", "value": "1022 °C" }, { "label": "Stiffness", "line": "Young's modulus is 41.4 GPa in the Wikipedia infobox, and 41 GPa on WebElements.", "benchmark": "elastic_modulus", "scope": "material", "value": "41.4 GPa" }, { "label": "Heat conduction", "line": "Thermal conductivity is 16.5 W/(m·K) in the Wikipedia infobox, 17 W/(m·K) on WebElements and 13 W/(m·K) from Goodfellow at 0 to 100 °C.", "benchmark": "thermal_conductivity", "scope": "material", "value": "16.5 W/(m·K)" }, { "label": "Laser wavelength", "line": "Nd:YAG emits at 1064 nm through a four-level transition, as the Wikipedia text states. The MOLA transmitter also operated at 1.064 µm.", "scope": "material", "value": "1064 nm" } ], "compare": "Neodymium is a light, soft rare-earth metal, with a density of about 7.0 g/cm3 and a melting point near 1022 °C. Its thermal conductivity of 13 to 17 W/(m·K) is low for a metal, and its Young's modulus of about 41 GPa is modest. Its value comes from its magnetic and optical behaviour rather than from its strength. The metal tarnishes in air and reacts with water, so it needs dry handling. No comparison profile is carried in this file, so the rows below list neodymium values only.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Keep the metal dry and sealed under light mineral oil, or in a dry inert atmosphere (Lesker MSDS).", "Keep it away from oxidizing agents, and do not agitate the fine powder in air (Lesker MSDS).", "Do not use water on a fire. Smother it with dry sand or a dry powder agent for metal fires (Lesker MSDS).", "Use local exhaust ventilation and a dust respirator if airborne levels exceed the limits (Lesker MSDS)." ], "good_for": [ "Nd:YAG laser media: the 1064 nm line was used for laser altimetry on Mars Global Surveyor (NASA).", "Permanent magnets: neodymium is the magnet element in Nd-Fe-B, used in motors and wind turbine generators (Wikipedia).", "Neodymium-glass lasers: the National Ignition Facility amplifies infrared pulses at about 1053 nm (Wikipedia)." ], "watch_out": [ "Fine chips, turnings and dust are flammable, and the metal can self-heat enough to ignite (PubChem, Lesker).", "The metal tarnishes in air and reacts with water and acids to release hydrogen (Wikipedia, Lesker).", "Supply is concentrated: China produced about 69 % of world rare-earth mine output in 2025, and neodymium is not named in the April 2025 Chinese export-control list (USGS).", "The sources disagree on several physical values, so each figure must be checked against its own source and conditions." ], "verdict": "Neodymium metal is a dense rare-earth metal with a melting point of 1022 °C. Its value is as the magnet element in Nd-Fe-B permanent magnets and as the active ion in Nd:YAG and neodymium-glass lasers, not as a structural metal. The metal needs dry handling, because its fines can ignite and it reacts with water.", "recipe": { "line": "Neodymium is a single-element metal (Nd). Wikipedia says the industrial route is electrolysis of neodymium oxide dissolved in a molten mixture of neodymium(III) fluoride and lithium fluoride, where the neodymium ions are reduced at the cathode and the molten metal collects at the bottom of the cell. Goodfellow says the metal is produced by calcium reduction of neodymium fluoride.", "parts": [ { "name": "Neodymium", "symbol": "Nd", "role": "The whole material. NIST prints the standard atomic weight as 144.242. Goodfellow pellets and foil are the forms sold.", "atoms": 1, "atomic_weight": 144.242 } ] }, "risk_groups": [ { "title": "For people", "lead": "The hazard is in the metal's form. Solid pieces are less hazardous than chips, turnings and dust, which can ignite, and the powder can irritate skin and eyes.", "points": [ { "label": "Chips and dust", "line": "Finely divided metal is flammable and can self-heat enough to ignite (Wikipedia). The 1996 Lesker sheet says grinding or cutting may form an explosive dust-air mixture." }, { "label": "GHS notifications", "line": "PubChem records H228 (flammable solid) in 34.3 % of 463 company reports and H251 (self-heating) in 33.3 %. 261 of the reports say the substance does not meet GHS criteria." }, { "label": "Skin and eyes", "line": "PubChem records H315 and H319 (skin and eye irritation) in 41.9 % of reports, and Wikipedia says the powder can irritate the skin and eyes." }, { "label": "Dust limit", "line": "The Lesker sheet lists a limit of 15 mg/m3 for neodymium, and warns that repeated overexposure to dust can scar lung tissue." } ], "level": 1, "verdict": "Fine dust and chips are the main concern" }, { "title": "If it fails", "lead": "The sources give three failure routes: a fire in fines, oxide spalling in air, and hydrogen release with water or strong acid.", "points": [ { "label": "Fire", "line": "Fines and turnings may ignite spontaneously in air or moisture. The Lesker sheet says to smother a fire with dry sand or a dry powder agent, and not to use water or CO2." }, { "label": "Air", "line": "The metal tarnishes in air, and the oxide can flake away and expose fresh metal to further oxidation (Wikipedia)." }, { "label": "Water and acids", "line": "Neodymium reacts with water to release hydrogen, slowly in cold water and faster in hot water. Strong acids may also release hydrogen (Wikipedia, Lesker)." } ] }, { "title": "Handling and storage", "points": [ { "label": "Keep it dry", "line": "Keep the metal dry and sealed, under light mineral oil or in a dry inert atmosphere. Handle powder in an inert atmosphere when machining (Lesker)." }, { "label": "Fire agents", "line": "Use dry sand or a dry powder agent for metal fires, and do not use water or CO2 extinguishers (Lesker)." } ] } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 28, "unreachable": 2, "caveats": 6, "note": "Read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable: the USGS 2025 critical minerals page and the EUR-Lex page for Regulation (EU) 2024/1252. Caveats: most physical values differ between sources, the hazard classifications are from a 1996 sheet and PubChem notifications, the production shares are for all rare earths, and the critical-mineral lists are empty." }, "sources": { "wikipedia-nd": { "title": "Neodymium (Wikipedia)", "url": "https://en.wikipedia.org/wiki/Neodymium", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" }, "pubchem-nd": { "title": "PubChem compound record: Neodymium (CID 23934), including ECHA C and L Inventory classification", "id": "CID 23934; CAS 7440-00-8; EC 231-109-3", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23934/JSON", "year": 2026, "kind": "database", "license": "PubChem (NCBI), public domain; sections attributed to ECHA and others" }, "webelements-nd": { "title": "WebElements: Neodymium, physical properties (University of Sheffield)", "url": "https://winter.group.shef.ac.uk/webelements/neodymium/physics.html", "kind": "database", "license": "WebElements, cited not reproduced" }, "goodfellow-nd-pellets": { "title": "Neodymium pellets, physical and thermal properties (Goodfellow product datasheet)", "url": "https://www.goodfellow.com/uk/neodymium-pellets-group", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" }, "goodfellow-nd-general": { "title": "Neodymium, rare-earth metals page (Goodfellow)", "url": "https://www.goodfellow.com/usa/material/rare-earth-metals/neodymium", "kind": "datasheet", "license": "supplier web page (cited, not reproduced)" }, "nist-nd": { "title": "NIST: Atomic Weights and Isotopic Compositions for Neodymium", "url": "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Nd&all=all", "kind": "database", "license": "NIST public domain" }, "lesker-nd-msds": { "title": "Kurt J. Lesker Company material safety data sheet: Neodymium (last revised 8/13/96)", "url": "https://www.lesker.com/newweb/deposition_materials/pdf/msds_nd.pdf", "year": 1996, "kind": "datasheet", "license": "supplier safety data sheet, cited not reproduced" }, "usgs-ree-2026": { "title": "Mineral Commodity Summaries 2026: Rare Earths (USGS)", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-rare-earths.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "mola-nasa-2000": { "title": "Space Operation of the MOLA laser (Afzal, NASA Goddard Space Flight Center, 2000)", "id": "NTRS 20000053090", "url": "https://ntrs.nasa.gov/api/citations/20000053090/downloads/20000053090.pdf", "year": 2000, "kind": "paper", "license": "public domain (NASA)" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/neodymium/" }