Magnetic and magneto-optical properties of Mn(Sb_1-xBi_x) thin films

Mn (Sb-Bi) alloy films with an NiAs-type structure were prepared by successive deposition of Mn layers onto Sb-Bi alloy layers, followed by annealing at temperatures up to 500°C. A single NiAs-type phase was obtained over the composition range 52 ≤ Mn ≤ 62 at%, 35 ≤ Sb ≤ 48 at%, 0 ≤ Bi ≤ 5 at%. Systematic experimental investigations of the magnetic and magnetooptical properties of these films were carried out. These investigations clarified (1) the dependences of M_s, H_c, and K_u on composition, and (2) the dependence of θ_K on the composition and the wavelength λ (0.4 to 1.1 μm). The magnitudes of M_s and θ_K were found to depend on the Mn content. Maximum values of M_s and θ_K were 600 emu/cm³ and 0.7° (at λ = 0.633 μm), respectively, for films containing 52 at% Mn. The maximum (positive) value of K_u (= 1 × 10⁶ erg/cm³) was obtained for films containing about 62 at% Mn.