热压烧结尖晶石多晶微波铁氧体材料研究

Study on microwave polycrystalline spinel ferrite sintered by hot pressing

采用普通陶瓷工艺制备了尖晶石多晶微波LiZn铁氧体XJ50粉料,采用热压烧结制备了铁氧体材料,研究了热压烧结工艺参数对材料微观结构、电磁性能的影响。结果表明,在实验烧结温度范围950~1020℃,各样品均具有致密、均匀的单相尖晶石LiZn铁氧体结构,气孔率P均小于0.75%;烧结温度980℃、400℃开始加压1 t的条件下,材料的电磁性能最好,饱和磁化强度4πM_(s)达到5017 G、铁磁共振线宽ΔH降低到150 Oe以下、自旋波线宽ΔH_(k)约为5.8 Oe;在1000℃的相同烧结温度下,热压烧结与普通烧结比较,4πM_(s)由4795 G提高到4880 G,ΔH降低了近15%,ΔH_(k)提高了约83%,材料的P由2%减小到0.7%。热压烧结制备的材料致密、均匀、晶粒小、电磁性能优良,是研制高性能铁氧体材料的有效途径。

Spinel microwave polycrystalline LiZn ferrite XJ50 powder was prepared by ordinary ceramic process,and ferrite materials were prepared by hot pressing sintering.The effects of hot pressing sintering process parameters on the microstructure and electromagnetic properties of the materials were studied.The results show that XJ50 materials sintered by hot pressing have dense and uniform single-phase spinel LiZn ferrite structure in the experimental sintering temperature range of 950℃to 1020℃,with porosity P of less than 0.75%;for the sintering temperature of 980℃and 400℃and pressure of 1 t,the material has the best electromagnetic properties,with 4πM_(s) of 5017 G,ferromagnetic resonance linewidthΔH of less than 150 Oe,and spin wave linewidth ΔH_(k) of about 5.8 Oe;for the same sintering temperature,compared with that of ordinary sintering,4πM_(s) of XJ50 material increases from 4795 G to 4880 G,ΔH decreases by nearly 15%,ΔH_(k) increases by about 83%,and the P of the material decreases from 2%to 0.7%.The material by hot pressing sintering features compact microsture,uniform and small grain size,better properties,and so hot pressing sintering is an effective way to prepare high-performance ferrite materials.