Room temperature magneto-electric coupling in La–Zn doped Ba_1−xLa_xFe_12−xZn_xO₁₉ (x = 0.0–0.4) hexaferrite

Abstract

Barium hexaferrite powder samples with substitution of La⁺³ at Ba⁺² and Zn⁺² at Fe⁺³ site, according to the series formula Ba_1−xLa_xFe_12−xZn_xO₁₉ (x = 0.0, 0.1, 0.2, 0.3, 0.4) have been prepared by the co-precipitation method. These samples were characterized by X-ray diffractometer (XRD), scanning electron microscopy, Polarization versus electric field loop tracer and vibrating sample magnetometer techniques. XRD patterns and Rietveld refinement indicate the single-phase formation of the magneto-plumbite barium hexaferrite for all the samples. Significant changes in dielectric properties are obtained by the different doping concentration of La and Zn. Ferroelectric loop for all the samples shows the lossy ferroelectric behaviour. Large spontaneous polarization is observed for x = 0.2 sample at room temperature. With increasing La and Zn doping content, the value of saturation magnetization and retentivity increases, and reaches a maximum value of 40.0 emu/gm and 24.0 emu/gm, respectively, for x = 0.2 sample and then decreases. To confirm the magneto-electric coupling, the second-order magneto-electric coupling coefficient β is measured through the dynamic method with the maximum value of ~ 1.69 × 10^− 6 mV/cm.Oe² for x = 0.2 sample at room temperature. The observations of room temperature magneto-electric coupling in these samples are useful for evolution of new multifunctional devices.