Magnetic and Dielectric Properties of Novel Low-Temperature Sintered High-Entropy Garnet Ferrites

Abstract

Yttrium iron garnet ferrite is widely used in microwave devices due to its excellent fundamental electromagnetic properties and easily adjustable magnetic properties. High-entropy garnets have begun to be investigated in recent years, but the choice of elements is currently limited. In this study, a series of bismuth-containing high-entropy yttrium iron garnet ferrite (Bi0.6Gd0.6Ho0.6Y0.6Re0.6)Fe5O12 (Re = Dy, Er, Tm, Yb) were successfully prepared by solid-phase reaction method. Bi3+ was incorporated into a high-entropy matrix for the first time and the sintering temperature was reduced. The effects of different ionic variables on magnetic and dielectric properties were investigated. After sintering at 1150 °C for 4 h, a single-phase garnet structure was obtained as confirmed by XRD Rietveld as well as TEM, which suggests that the incorporation of Bi3+ with large ionic radii does not lead to the formation of heterogeneous phases under high-entropy conditions. The high-entropy garnet samples have unique magnetic properties and high dielectric constants, among which (Bi0.6Gd0.6Ho0.6Y0.6Yb0.6)Fe5O12 has a better overall performance, ε' = 19.57, Bm = 899 Gs. This paper broadens the field of research on high-entropy garnet ferrites.

Keywords: YIG, High entropy ceramics, magnetic properties, Dielectric constant