Samarium
A rare-earth metal used as feedstock for samarium–cobalt (SmCo) permanent magnets that retain performance at high temperature and in corrosive environments. Distinct from finished SmCo magnet products already catalogued separately.
Overview
Samarium (symbol Sm, atomic number 62) is a silvery rare-earth metal with a density of about 7.52 g/cm³ and a melting point near 1072°C. Automotive and mobility relevance centres on samarium–cobalt magnet feedstock (SmCo5 and Sm2Co17 families), which offer superior thermal stability and corrosion resistance versus NdFeB at the expense of lower remanence and higher cobalt content. SmCo magnets appear in high-temperature sensors, aerospace-derived actuators, specialised pumps and niches where demagnetisation risk or corrosive atmospheres preclude NdFeB. Samarium is also used in infrared-absorbing glasses, catalysts and some nuclear-control applications. As a middle rare earth, samarium is co-produced in light-to-medium REE separation circuits dominated by China, with secondary streams from Australia and other projects. This record covers elemental/oxide/metal feedstock; finished SmCo magnet articles should be referenced as separate material entries where they exist.
Automotive Applications
Properties
Category
Type
Rare Earth Element
Available Colors
Available Forms
Key Properties
- Feedstock for SmCo5 and Sm2Co17 magnet systems
- Superior high-temperature stability vs NdFeB
- Requires cobalt co-alloying in finished magnets
- Middle rare-earth co-product of REE separation
- More corrosion-resistant magnet systems than uncoated NdFeB
- Lower remanence / higher cost than NdFeB for mainstream traction
Technical Specifications
Density
7.52 g/cm³
Tensile Strength
Not used as a structural metal; consumed as SmCo magnet feedstock
Temperature Resistance
Melts at ~1072°C; SmCo magnets commonly rated for continuous use above 250–300°C depending on grade
Sustainability
Sustainability Rating
Samarium in SmCo scrap can be recovered through established rare-earth recycling routes, but volumes are smaller than NdFeB streams. Primary REE separation remains chemically intensive and geographically concentrated. Cobalt content in finished SmCo magnets adds a second critical-materials dependency beyond samarium itself.