Exploration of ions diffusion and regulation of electromagnetic performance for reconfigurated LZ/NCZ composite ferrites

Abstract

Traditional Li-based and Ni-based spinel microwave ferrites have triggered tremendous interests, due to the excellent squareness Br/Bs and high Curie temperature Tc of Li-based ferrites, and low ferromagnetic resonance FMR linewidth ΔH and low coercivity Hc of Ni-based ferrites, respectively. However, to meet the requirement of excellent temperature stability and low insertion loss of microwave/millimeter devices and components, the challenges remain to compromise the contradiction between ΔH and Tc for traditional spinel microwave ferrites such as low ΔH and high Tc. In order to make a breakthrough, herein, we explore introduce NiCuZn (NCZ) ferrites to LiZn (LZ) ferrites to synthetize a facile material LZ/NCZ composite microwave ferrites. The ions diffusion, static magnetic properties, ΔH and microwave dielectric performances have been systematically investigated. With the increase of sintering temperature from 800 °C to 1200 °C, the LZ/NCZ composite ferrites transfer from independent NCZ and LZ ferrites to homogeneity LNCZ ferrites. It is confirmed that the ΔH (247Oe ∼ 163Oe) and Tc (403 °C∼332 °C) of LZ/NCZ ferrites can be tunable and are directly determined by the NCZ doping contents (0 wt% ∼ 100 wt%). The sample with 40 wt% NCZ possesses optimum comprehensive performance with high saturation magnetization (Ms, 401 kA/m), high remanence (Br, 365 mT), high Curie temperature (Tc, 367 °C), low coercivity (Hc, 78A/m), low dielectric loss (tanδ, 2.61 × 10−4), and relative low FMR linewidth (ΔH, 207Oe). The state-of-the-art of LZ/NCZ composite ferrites with promising magnetic and electrical performances exhibit great potential for phase array radar systems operating in wide temperature range.