“Samarium” – Though Lacks a Legendary Story, Its Magnetic Power Ranks Just Below Neodymium Magnets

Introduction

Samarium was first discovered in 1879 by French chemist Paul-Émile L. de Boisbaudran from the rare earth mineral samarskite, which was itself named in honor of Russian mining engineer Colonel Vasili Samarsky-Bykhovets for his contributions to mineralogy.

Samarium has seven naturally occurring isotopes, including stable isotopes ¹⁴⁴Sm, ¹⁴⁹Sm, ¹⁵⁰Sm, ¹⁵²Sm, and ¹⁵⁴Sm, as well as the long-lived primordial radioisotope ¹⁴⁷Sm, along with 31 artificially synthesized radioactive isotopes.

Samarium is not found as a free element in nature but rather as a component of rare earth minerals like monazite, bastnäsite, cerite, beryllium silicate, and samarskite, with the main ores being monazite sand and bastnäsite.

Samarium (Sm)

Atomic number: 62

Atomic weight: 150.36 u

Atomic structure: The outermost electronic structure of samarium is 4f⁶ 6s²。

Physical/chemical properties: It is a medium-soft metal with silvery white luster. It will oxidize slowly in dry air and is not easy to corrode. Samarium is prone to spontaneous combustion at temperatures of 150°C.

Main Application Areas of Samarium

• Magnetic Materials: As one of the most demagnetization-resistant elements, samarium is widely used in high-performance permanent magnets, with the primary commercial application being samarium-cobalt magnets.
  
  • These materials, with exceptional magnetic properties just below that of neodymium magnets, are used in permanent magnetic motors, disk drives, audio equipment, magnetic separators, and other applications.
    
• Nuclear Energy: The naturally occurring isotope ¹⁴⁹Sm has strong neutron-absorbing capabilities and can serve as a material in nuclear reactor control rods.
  
• Medical Applications: The synthetic isotope ¹⁵³Sm is used in radiation therapy for treating cancers such as lung, prostate, and breast cancers, as well as bone conditions like skeletal cancer and arthritis. It is typically infused into patients to deliver targeted radiation treatment to affected areas.
  
• Electronics: Samarium is used as a phosphor in electronic components, useful for displays, TV screens, and lighting applications due to its ability to produce various colors of light.
  
• Optical Glass: Samarium glass, known for its optical properties, is used in laser components, optical filters, and fiber optic amplifiers.
  
• Scientific Research: In laboratory settings, samarium is used for academic research, particularly in nuclear physics and materials science, to explore its properties and potential applications.
  
• Other Applications: Samarium oxide, an effective infrared absorber, is often added to specialty glass and infrared-sensitive phosphors. It also serves as a catalyst in chemical reactions and is used in lasers, mixed rare-earth alloy flints, masers, and more.