Alnicos

Alnicos ;are a group of heat-treated Fe–Co–Ni–Al–Cu alloys that can be divided into two main subgroups: isotropic alloys containing 0–20 wt.% Co (alnicos 1–4) and anisotropic alloys with 22–24 wt.% Co and titanium content of 5–8 wt.% (alnicos 5–9). The anisotropy in the case of alnicos 5–9 is produced by controlled cooling or isothermal heat treatment in a saturating magnetic field. The main source of anisotropy is the shape anisotropy associated with elongated Fe–Co particles in a Ni-Al matrix aligned parallel to the magnetic field during spinodal decomposition of the alloy. Alnicos are widely used as permanent magnets. The most important applications are loudspeakers, watt-hour meters, electric motors, generators, and alternators.

Samarium–cobalt magnet

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.

Attributes

Extremely resistant to demagnetization