Epitaxial NiMnSb films on GaAs(001)

Abstract

We show the growth of epitaxial NiMnSb(001) thin films, a half-metallic ferromagnet, on GaAs(001) by molecular-beam epitaxy. The Sb content of the films strongly depends on the Sb flux. Sb-deficient films show a reduced magnetization and the formation of a Mn2As interface layer. Stoichiometric films exhibit the bulk lattice constant, have a saturation magnetization close to the bulk value, and do not suffer from Mn2As formation at the interface. They show in-plane uniaxial anisotropy with nearly square hysteresis loops along the easy axis, which points either along [110] or [11̄0] depending on the growth conditions.