The family is named for German mining engineer and chemist Friedrich Heusler, who studied the ferromagnetic compound Cu₂MnAl in 1903.
Cu₂MnAl reaches about 8,000 gauss room-temperature saturation induction with a Curie temperature of 357 °C (Oxley), its ~3.7 Bohr magneton moment residing almost solely on manganese atoms; Bradley and Rogers showed in 1934 that the ferromagnetic phase is the fully ordered L2₁ structure.
De Groot et al.'s study of the half-Heusler NiMnSb opened the half-metallic ferromagnet class — metallic in one spin channel, gapped in the other — now central to spintronics.