Room-temperature magnetoelectric effect in Al-doped Sr3Co2(Fe1-xAlx)24O41 hexaferrites

Here we present the results of a systematic investigation of the effect of Al doping on the roomtemperature magnetoelectric properties of Z-type hexaferrites of the composition Sr3Co2(Fe1-xAlx)(24)O-41 where x = 0, 0.02, 0.04, and 0.08. Aluminum doping is shown to stabilize the transverse conical spin structure and increase the range of magnetic fields in which the ferroelectric phase occurs for x <= 0.04. These characteristics are attributed to the favoring of the easy-axis magnetic anisotropy over the easy-plane brought about by Al doping. Furthermore, when x approaches 0.08, switching of the magnetic field leads to switching of the ferroelectric polarization, which is attributed to the transformation of the transverse conical spin structure into a new structure. (C) 2019 Elsevier B.V. All rights reserved.