La_2O_3-B_2O_3-ZnO玻璃助剂对低温烧结LiZn铁氧体旋磁特性及微观结构的影响

采用固相法制备了La_2O_3-B_2O_3-ZnO(LaBZ)玻璃掺杂改性的LiZn铁氧体。为了满足LiZn铁氧体低温共烧和叠层片式微波铁氧体器件的要求,系统研究了LaBZ玻璃对LiZn铁氧体的烧结特性、微观结构以及旋磁特性的影响。结果表明,在900℃烧结可以得到纯的尖晶石相,通过液相烧结,LaBZ玻璃显著提升了LiZn铁氧体的致密度,晶粒尺寸以及旋磁特性。与未添加助熔剂的材料相比,900℃烧结、掺杂1wt%LaBZ玻璃助熔剂饱和磁化强度Ms增高(300 kA/m,4pMs=3777 G),剩磁比增大(～0.85),矫顽力(～189 A/m)下降,同时铁磁共振线宽减小(～256 Oe, 9.5 GHz)。由于富集于晶界的LaBZ非磁性另相的影响,其Ms值比同成分低温共烧LiZn铁氧体的Ms值400k A/m(4pMs=5000 G)低了25%,而线宽值高了35%。

Effects of La_2O_3-B_2O_3-ZnO glass additive on the gyromagnetic properties and microstructure of low temperature sintered LiZn ferrites

La2O3-B2O3-ZnO (LaBZ) modified LiZn ferrites were prepared by conventional solid-state reaction method.The effects of LaBZ glass additions on the sintering characteristic,microstructure and gyromagnetic properties of low temperature sintered LiZn ferrites were systematically investigated in order to assess the potential applications of LiZn ferrites in low temperature co-fired ferrite (LTCF) and produce gyromagnetic devices with a multilayer process.The results show that a pure spinel phase can be formed at 900 ℃,the LaBZ glass additions in the LiZn ferrites contributes remarkably increase to the densification,grain size and gyromagnetic properties via a liquid phase sintering.The samples sintered at 900 ℃ with 1 wt% amount of LaBZ glass additions can increase saturation magnetization (300 kA/m,4πMs =3777 G) and remanence ratio (about 0.85) and decrease coercivity (about 189 A/m) as well as drastically reduce ferromagnetic resonance line width (about 256 Oe) at 9.5 GHz compared to sample without LaBZ addition.Due to the influence of the non-magnetic LaBZ other phase,its M s value 300 kA/m (4πMs =3777 G) is significantly lower than the Ms value 400 kA/m (4πMs =5000 G) of the latter,while the line width increases.