Magnetic and magnetoelectric properties of substituted M-type SrScxFe12 – xO19 hexaferrites

Abstract

The anisotropic magnetic and magnetoelectric properties of single crystals of substituted M-type SrSc_xFe_{12 – x}O₁₉ (x = 1.4–1.7) hexaferrites are studied at temperatures of 2–800 K in magnetic fields up to 50 kOe. A spontaneous transition from a collinear ferrimagnetic single-axis phase to a conical structure is detected in all compositions, the transition temperature increases with the Sc concentration, and the Curie temperature decreases with increasing Sc concentration. The conical magnetic structures exhibit an electric polarization (more than 40 μC/m² at T = 4 K) induced by a magnetic field. The conditions of appearance of the polarization indicate that it is caused by the inverse Dzyaloshinskii–Moriya interaction. The dependences of the polarization on the value and the orientation of a magnetic field are investigated, and the possibilities of controlling the chirality of a conical structure, which determines the sign of polarization, are demonstrated.