Low Temperature Synthesis Of Low Coercive Force Lizn Ferrite Materials

Studying the process of low-temperature sintering the low coercively LiZn ferrite is important to optimize the performance index of phase shifter, improve the consistency of amplitude and phase, reform the process capability of material and increase the yield of microwave devices.Aiming at the object of low-temperature sintering the low coercively LiZn ferrite, the conventional ceramic process and Sol-Gel process were studied in this paper. Baseing on the request of low coercivity and high squareness in application , we had confirmed the main formulation of the LiZn ferrite ;during the study of the conventional ceramic process,With the main formula foundation, we mainly studied the influence of Ti4+,Co3+on lowering coercivity and Bi2O3,V2O5 on lowering sinter temperature.The results showed Bi2O3 good characteristic on lowering sinter temperature and the sample which mixed with 1% Bi2O3 could reduce 40% coercivity through slowing heating rate and extending the holding time. During the study of Sol-Gel process, we successfully synthesized the series of nanometer powder of the LiZn ferrite by citric acid self-propagating method, studied the influence of the value of pH ,the rate of citric and the calcinations temperature, discovered the optimum conditions to synthesize nanometer powder of the LiZn ferrite. The nanometer powder had lower sintering temperature than oxide powder because of its high surface activation and the difficulty of sintering fine material because of gas transport process predominating the sinter process .Through the research of the present stage, The researching results can provide the reference for low-temperature sintering the low coercively LiZn ferrite which is important to improve the performance of microwave ferrite for phase shifter.