  Half-metallic ferromagnets can produce fully spin-polarized conduction
electrons and can be applied to fabricate spintronic devices. Thus, in this
study, the electronic structure, magnetic properties, and optical properties of
GaSb, which has exhibited half-metallicity, doped with Mn, a 3d transition
metal, are calculated using the generalized gradient approximation and
Heyd-Scuseria-Ernzerhof (HSE) functional. Ga$_{1-x}$Mn$_x$Sb ($x = 0.25, 0.5,
0.75$) materials exhibit ferromagnetic half-metallic properties and a high
Curie temperature, indicating that this series can applied in spintronic
devices. Meanwhile, they absorb strongly in the infrared band, suggesting that
Ga$_{1-x}$Mn$_{x}$Sb also has potential applications in infrared photoelectric
devices.
