SmCo is a rare earth magnet made from an alloy of Samarium and Cobalt to form SmCo5 or Sm2Co17 compounds. Reed Switch applications that require stronger magnets and excellent thermal stability up to temperatures of 300C can use SmCo magnets.
A samarium–cobalt (SmCo) magnet, a type of rare-earth magnet, is a strong permanent magnet made of two basic elements: samarium and cobalt.
They were developed in the early 1960s based on work done by Karl Strnat at Wright-Patterson Air Force Base and Alden Ray at the University of Dayton. In particular, Strnat and Ray developed the first formulation of SmCo5.
Samarium–cobalt magnets are generally ranked similarly in strength to neodymium magnets, but have higher temperature ratings and higher coercivity.