Synthesis of nickel zinc ferrite ceramics on enhancing gyromagnetic properties by a novel low-temperature sintering approach for LTCC applications

Saturation magnetization and ferromagnetic resonance linewidth are important parameters for microwave devices, such as circulator/isolator. Conventional sintering of ferrite ceramics is prevalently performed to promote the densification. Here, we present a new sintering approach for obtaining uniform and dense NiCuZn ferrite ceramics with enhanced gyromagnetic properties at low temperatures. The NiZn-series ferrites (Ni 0.2 Cu 0.2 Zn 0.6 Fe 2 O 3 – 1.0  wt% Bi 2 O 3 +0.5  wt% MnO 2 ) was synthesized by solid reaction routes with new sintering approaches. The results indicate that a one-transient-step sintering process (OTSP) can significantly improve the gyromagnetic properties at low sintering temperatures by suppressing the anomalous grain growth, such as higher saturation magnetization (4π M s  = ∼3904 Gauss) and lower ferromagnetic resonance linewidth ( ΔH  = ∼170 Oe). Therefore, such a methodology is quite significant due to it provides a referential experience for effective sintering route that can enable broad practical applications, such as other ferrite ceramics.