Nano-TiO2 substituted LiZnBi ferrite ceramics with low sintering temperature and enhanced magnetic properties for LTCC applications

Abstract

Saturation magnetization (4πMs) and ferromagnetic resonance linewidth (ΔH) are vital parameters for microwave devices application. The material with high 4πMs and low ΔH is available in microwave frequency. In this work, to synthesize a ferrite material applied to X band, high saturation magnetization LiZnBi ferrite ceramics were selected as matrix. Further, in order to reduce magnetic loss of the LiZnBi ferrites sintered at low temperatures, various nano-TiO2 were added. Interestingly, the nano-TiO2 can promote grains growth and suitably enhance saturation magnetization and lower coercivity at low sintering temperature. Meanwhile, the ferromagnetic resonance linewidth (ΔH) of the ferrites can also be reduced by introducing more nano-TiO2 particles. At last, a nano-TiO2 substituted LiZnBi ferrite ceramics (x = 0.25) with high saturation magnetization (4πMs = ∼3367 G), low coercivity (Hc = ∼146.2 A/m) and low ferromagnetic resonance linewidth (ΔH = ∼192 Oe) were obtained at 880 °C. The ferrite material is serviceable for X band microwave devices, such as phase shifter and circulator.