Ultrasonic-induced enhancement in interfacial exchange coupling of composite ferrites via chemical co-precipitation

Ultrasonic technique has been introduced into a chemical co-precipitation method to successfully fabricate and well control interfacial structures of composite ferrites consisting of M-type barium hexaferrite (BaM, BaFe12O19)/nickel-zinc ferrite (NZ ferrite, Ni0.5Zn0.5Fe2O4). With a proper inputting ultrasonic power, the interfacial structures as NZ tiny particles attaching to BaM ferrite particles form, resulting in enhancement in interfacial exchanging coupling between the individual ferrite phases, and the synthesized nano-composites demonstrate a high magnetization of 57.5 emu/g and a coercive filed of 2750 Oe. The ultrasonic technique acted an important role in improving the elemental homogeneity in the precursor powders and therefore took effect on altering the nucleation and growth-up processes of the individual ferrite phase, which provides an effective way to control the interfacial structures in the composite ferrites. (C) 2019 Elsevier B.V. All rights reserved.