Low-temperature sintering LiZnTiMn ferrite ceramics: synthesis, microstructure, and enhanced ferromagnetic properties with CuO–V2O5 additive

Abstract

In this study, a new method was developed for the coexistence of different grain sizes and the densification of low-temperature sintered Li0.42Zn0.27Ti0.11Mn0.1Fe2.1O4 (LiZnTiMn) ferrite ceramics. Excellent gyromagnetic performance was realized for the LiZnTiMn ferrite ceramics by controlling the amount of CuO–V2O5 sintering additive. In particular, the appropriate amount of CuO–V2O5 sintering additive effectively restrained the abnormal grain growth and enhanced the densification of low-temperature sintering ferrite ceramics. In addition, scanning electron microscopy images indicated different grain sizes (large grains of ~ 10 µm and small grains of ~ 2 µm) because of the existence of V2O5–CuV2O6 eutectic compounds. The addition of the optimum amount of CuO–V2O5 resulted in LiZnTiMn ferrite ceramics with high saturation magnetization and low coercivity (ferromagnetic resonance line width was narrow). For the sample with 0.5 wt% CuO–V2O5 additive, a pure spinel phase was synthesized at a low firing temperature (~ 900 °C). In addition, the sample possessed significantly enhanced microwave ferromagnetic properties: Ms = 78.56 emu/g, Br/Bs = 0.85, Hc = 167 A/m, and △H = 167 Oe, making it useful as a new type of gyromagnetic material. These newly developed ceramic materials could be suitable candidates for microwave low-temperature co-fired ceramic gyromagnetic devices.