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 first forming an oriented SbBi layer by vapor deposition and annealing, then depositing an Mn layer onto this SbBi layer at an appropriate substrate temperature, and finally 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 Ku and Kerr rotation angle ¿K were carried out for the Mn(SbBi) films. As a result, substitution of Bi for Sb led to 1) an increasing Ku value, and 2) a change in the wavelength dependence of ¿K. The maximum observed values of Ku and ¿K were 4.5 × 10⁶ erg/cm³ and 0.5° at Hex = 7 kOe.