The high-temperature magnet metal that export controls just put back in the spotlight.
Samarium’s defining commercial use is samarium-cobalt (SmCo) permanent magnets, which retain magnetic strength at far higher temperatures and resist corrosion better than the more common neodymium-iron-boron magnets. That makes them the material of choice in aerospace, defense, and high-temperature motor applications where NdFeB would degrade. Samarium is also a strong neutron absorber, giving it a niche role in nuclear reactor control.
New to drill results? Read our guide: How to read assay results →
Isotope reference
Samarium-144 (¹⁴⁴Sm) is a naturally occurring stable isotope. CIAAW lists it at 0.0308(4) of normal terrestrial samarium (about 3.08%), while NIST lists the isotope mass as 143.911998 u.
| Isotope | Natural abundance | Half-life / status |
|---|---|---|
| ¹⁴⁴Sm | 3.08(4)% | Stable |
| ¹⁴⁷Sm | 15.00(14)% | 1.06(1) × 10¹¹ years |
| ¹⁴⁸Sm | 11.25(9)% | 7(3) × 10¹⁵ years |
| ¹⁴⁹Sm | 13.82(10)% | Stable |
| ¹⁵⁰Sm | 7.37(9)% | Stable |
| ¹⁵²Sm | 26.74(9)% | Stable |
| ¹⁵⁴Sm | 22.74(14)% | Stable |
CIAAW amount-fraction uncertainties are shown in parentheses where reported. “Stable” means no radioactive half-life is assigned in this table.
The isotope-specific status matters: natural samarium also contains long-lived radioactive Sm-147 and Sm-148, but Sm-144 is classified as stable. Consult evaluated NNDC nuclear data for decay and radiation details rather than inferring them from the element name.
Natural-element abundance does not make an isotope or a chemical product “safe.” Enriched, separated, or activated material can require controls that are not addressed by a general chemical SDS.
Supplier documentation
The linked document is a supplier SDS for samarium(III) oxide powder, not for isolated Sm-144. It is useful for the named chemical form and product specification only; it does not establish the radiological status of enriched or activated samarium.
Use this SDS only for the supplier’s oxide powder and confirm the current lot, packaging, and workplace requirements before handling.
An SDS is product-, supplier-, grade-, and form-specific. It is not a substitute for radiological review, institutional procedures, or the current documentation supplied with a particular isotope or lot.
Samarium oxide, 99.5% minimum, free on board • As of 2025 average
The USGS-reported average rose from $2.03/kg in 2021 to $3.34/kg in 2022, eased to about $2.00/kg in 2023–2024, then increased to $2.82/kg in 2025. China’s April 2025 export controls added a new constraint to the small SmCo-focused market.
Source: USGS Mineral Commodity Summaries 2026, Rare Earths (February 2026)
The primary traded form and a feedstock for magnets and other samarium compounds.
A high-temperature permanent-magnet material used in aerospace, defense, and specialty motors.
A soluble precursor used in catalysis and materials synthesis.
Direct Answers
Samarium’s primary commercial use is in samarium-cobalt permanent magnets, valued for retaining magnetic strength at high temperatures in aerospace, defense, and specialty motors. It is also used as a neutron absorber in nuclear reactor control.
Samarium itself is paramagnetic, but its alloy with cobalt is strongly ferromagnetic and used to make some of the most temperature-resistant permanent magnets available.
The USGS reported a 2025 average of $2.82/kg for samarium oxide at 99.5% minimum purity, free on board, up from roughly $2.00/kg in 2023–2024. This is historical context rather than a live quote.