掺镍钛酸钡纳米粉体及其陶瓷的溶胶-凝胶制备

Sol-gel preparation of Ni-doped BaTiO_3 nanosized powders and ceramics

目的研究焙烧温度和烧结温度对由溶胶-凝胶法制备的掺镍钛酸钡样品微结构及介电性能的影响。方法采用溶胶-凝胶法制备了掺镍钛酸钡粉体及其陶瓷，通过FT-IR，XRD，SEM和TEM对干凝胶粉体、预烧粉体以及陶瓷进行了表征，并测定陶瓷的介电性能。结果采用溶胶-凝胶法可制备纳米级（30～80nm）掺镍钛酸钡粉体及其细晶陶瓷（1—3μm）；较高的焙烧温度有利于四方相钛酸钡的形成和晶粒的长大，但降低了陶瓷的介电常数；较高的烧结温度有利于陶瓷居里点介电常数的提高，合适的焙烧温度及烧结温度分别为800℃和1300℃。结论溶胶-凝胶法可制得组成均匀、性能优异的介电材料，是制备多组分掺杂钛酸钡陶瓷的理想方法。

Aim To study the effects of calcining temperature and sintering temperature on the microstructures and dielectric properties of the ceramics prepared by the Sol-Gel process. Methods The powders and ceramics of Ba- TiO3 doped with nickel were prepared by a Sol-Gel process. The dry gel, powders and ceramics were characterized by FT-IR, XRD, SEM and TEM methods. Results The result shows that the nanosized powders with particles of 30 ～ 80 nm and fine-grained ceramics of 1 -3μm can be prepared by the Sol-Gel process. Higher calcining temperature is of benefit to the formation of tetrahedron BaTiO3 phase and growth of the grain. And the higher sintering temperature is good for increasing of dielectric constant at Curie temperature. Conclusion： The optimum Calcining and sintering temperatures are 800℃ and 1 300℃ respectively. Since the Sol-Gel process is very good for the modification of ceramic dielectric property, it is an ideal method to prepare the BaTiO3 doped with many additions.