Magneto-optical and magnetic properties of some solid solutions of C1b-Heusler compounds

The large Kerr effect in PtMnSb has been ascribed to details of its unusual band structure. Substitution of atoms will modify the band structure and consequently alter the Kerr effect. In the present investigation we have determined the magneto-optical properties at room temperature in the energy range 0.5–5 eV of several solid solutions of C1_b−Heusler compounds, comprising the solid solution series Pt_1−xNi_xMnSb, Pt_1−xRh_xMnSb, Ni_1−xCr_xMnSb, Ni_1−xFe_xMnSb and PtMnSb_0.9Sn_0.1. The magnetic and crystallographic properties were determined for the solid solution series Pt_1−xNi_xMnSb, Pt_1−xRh_xMnSb and Ni_1−xCr_xMnSb. Neither of the substitutions leads to a larger Kerr effect than that present in the pure compound. Moreover, it is found that the shape of the spectra does not change significantly. For one case, Ni substituted in PtMnSb, band structure calculations were made for hypothetically ordered compounds. The results agree with the experimental findings that near 1.7 eV magneto-optically active transitions persist on substituting Ni in PtMnSb.