Effects of Ni2+ concentration on the composition, structure, magnetic properties, and DC-bias superposition characteristics of NiCuZn ferrites

NixCu0.2ZnyFe1.98O4 (x = 0.16, 0.26, 0.35, 0.43, 0.50; y = 0.8-x) ferrites were prepared via solid-state reaction. The influence of Ni2+ concentration on ferrites composition, microstructure, magnetic properties and DC-bias superposition characteristics was studied by XRD, SEM, XPS, and VSM. Then, the effect of magnetic properties on the DC-bias superposition characteristics was analyzed. The results showed that the ferrites sintered at 900 ?& nbsp;for 3 h were all in pure spinel phase with an average grain size of 7.5 mu m and a relative density of about 5.15 g cm(-3). With the increase in Ni2+ concentration, the saturation magnetization (M-s) and coercivity (H-c) of ferrites increased, but the magnetocrystalline anisotropy constant (K-1) first increased and then decreased. And the M-s, H-c, and K-1 of the specimen with x = 0.43 were 63.62 emu.g(-1), 27.36 Oe, and 1813.17 Oe.emu.g(-1), respectively. In particular, the specimen of x = 0.50 achieved the best DC superposition characteristics, where the H-70% was about 220 A m(-1). The incremental permeability of the specimens decreased rapidly at a bias magnetic field < 400 A m(-1). The variation mainly originated from the domain wall displacement, and the rate of decrease was influenced by both M-s and K-1. At a bias magnetic field >= 400 A m(-1), the incremental permeability of the specimens decreased slowly, mainly because the number of domain walls decreased until disappearing, and the specimens tended to become a single domain structure. And the rate of decrease of incremental permeability was mainly affected by K-1.

Automated summary

In this study, NixCu0.2ZnyFe1.98O4 ferrites with different Ni2+ concentrations were prepared via solid-state reaction, and the influence of Ni2+ concentration on the composition, microstructure, magnetic properties, and DC-bias superposition characteristics of the ferrites was investigated. The results showed that increasing Ni2+ concentration resulted in improved magnetic properties, and the specimen with a Ni2+ concentration of 0.50 exhibited the best DC superposition characteristics.