溶胶-凝胶法制备钛掺杂BaFe_(12)O_(19)陶瓷

Preparation of Ti Doped BaFe_(12)O_(19) Ceramics by a Sol-Gel Process

通过溶胶-凝胶法制备了钛掺杂的M型钡铁氧体BaFe12-xTixO19（BFTO）粉末以及陶瓷材料。利用X射线衍射谱对掺杂体系的物相形成进行了研究，利用扫描电子显微镜对掺杂体系的结晶形貌进行了观察，采用磁学测试系统和阻抗分析仪测试了掺杂体系的磁学性能。结果表明：800℃可以得到结晶性较好的BFTO原料粉末，并在1200℃可烧结得到晶型完整的钡铁氧体相陶瓷，其烧结温度比未掺钛钡铁氧体相陶瓷低约100℃。这种陶瓷的磁导率≥5，比未掺钛陶瓷的提高了3～4倍，且频率稳定性好（≤70MHz时基本保持不变）。陶瓷相应的矫顽力下降≥65％，饱和磁化强度和剩余磁化强度仅降低10％～15％。在相关器件中使用时，有望在保持高剩余磁化强度的同时有效地降低能耗，显著改善器件的性能，推动相关领域向小型化和微型化发展。

Ti doped M-type barium ferrite powders and ceramics of BaFe12-xTixO19（BFTO） were prepared by a sol-gel method. The phase structure and morphology were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The magnetic properties were analyzed by magnetic property measurement system and impedance analyzer. The result shows that the BFTO raw material powders can be obtained by heat-treatment at 800 ℃. There exists barium ferrite phase in all the BFTO ceramics sintered at 1 200 ℃ or 1 300 ℃ after pretreated at 800 ℃. The highly compact BFTO ceramic with x of 0.8 can be obtained when sintered at 1 200 ℃. The permeability of the ceramics increases to more than 5, which is 3--4 times greater than that of BFO ceramics, showing a good frequency stability at below 70 MHz. The coercive force is decreased by 〉 65%, and the saturation magnetization and residual magnetization are decreased by 10 %- 15 %. It is appropriate for BFTO ceramics used in the related devices to effectively reduce energy intensity, simultaneously remain high residual magnetization, and improve the properties of the devices.