The influence of deposition conditions on the magnetic properties in PtMnSb films

The dependence of magnetic properties on preparation conditions and annealing temperature of PtMnSb intermetallic compound has been investigated. Samples were prepared by sputter deposition on an SiO₂ substrate under different sputtering conditions. Magnetic properties of as-deposited films were strongly related to argon sputter gas pressure (P_Ar) and substrate temperature during sputtering. The anisotropy changes from parallel to perpendicular to the substrate plane P_Ar=30 mTorr and coercivity as high as 400 Oe was obtained at 40 mTorr. Annealing over 350°C led to an increase in Θ_k for all samples. K_u⊥ of 2×10⁴ erg/cm³ and H_c⊥ of 800 Oe were obtained by annealing at 450°C for the films deposited over about P_Ar=20 mTorr. The angular dependence of H_c for these samples is fairly large and qualitatively in agreement with simple Stoner-Wohlfarth behavior. Scanning electron microscope (SEM) observation clarified that such films are composed of PtMnSb columns, which behave like single-domain particles