Magnetic and magnetooptical properties of Mn(Sb-Bi) thin films fabricated by the interdiffusion method

NiAs-type Mn (SbBi) alloy films, with c-axes oriented perpendicular to the film surface, were obtained in the composition range 45 < Mn < 65 at%, Bi < 10 at% by forming an oriented SbBi layer by vapor deposition and annealing, depositing an Mn layer onto this SbBi layer at an appropriate substrate temperature and annealing at temperatures up to 500°C. Several different phases appeared in these films, the matrix of which was the NiAs-type Mn (SbBi) phase. It was found that the phases and lattice constants of Mn (SbBi) change on increasing the annealing temperature. Systematic experiments on the magnetic anisotropy constant K_u and the Kerr rotation angle θ_K were carried out. It was found that substitution of Bi for Sb led to an increased K_u value and a change in the wavelength dependence of θ_K. The maximum observed values of K_u and θ_K were 4.5 × 10⁶ erg/cm³ and 0.5°, respectively, at H_ex = 7 kOe.