Li_2CO_3掺杂BaTiO_3无铅压电陶瓷的低温烧结

Low Temperature Sintering of Li_2CO_3 Doped BaTiO_3 Lead-Free Piezoelectric Ceramics

以Li2CO3作为烧结助剂,采用传统固相烧结法制备BaTiO3陶瓷。研究了烧结温度(1000~1150℃)和Li2CO3添加质量分数(0%~5%)对BaTiO3陶瓷结构和电学性能的影响。结果表明:Li2CO3的掺入有效地促进了陶瓷的烧结,使BaTiO3的烧结温度从1300℃以上降低到1050℃。X射线衍射结果表明:未掺Li2CO3的BaTiO3陶瓷样品为四方相结构,掺Li2CO3的BaTiO3陶瓷样品为正交相结构。Li2CO3掺量为1%的陶瓷样品具有较高的致密度,且在1050℃时获得最大值,其相对密度可达94%。当烧结温度为1100℃时,BaTiO3陶瓷的压电常数d33获得最大值,且d33随着Li2CO3掺量的增加而降低。其中Li2CO3掺量为1%时陶瓷具有较好的电性能:d33=200pC/N,εr=1322,TC=115℃。

Li2CO3 doped BaTiO3 ceramics were prepared by conventional sintering technique. The influences of sintering temperature and Li2CO3 doping contents on the crystalline structure and piezoelectric properties were investigated. The results reveal that Li2CO3 significantly promotes the sinterability of BaTiO3 ceramics, in which the densification sintering temperature of BaTiO3 is reduced from 1300 ℃ to 1050 ℃ by adding only 1 wt% Li2CO3. XRD pattern indicates that the pure BaTiO3 is tetragonal phase while Li2CO3 doped BaTiO3 is orthorhombic phase. BaTiO3 with 1 wt% Li2CO3 ceramics sintered at 1050 ℃ have the highest relative density of 94%. The 1 wt% Li2CO3 doped BaTiO3 ceramics sintered at 1100 ℃ show the highest electrical properties. with d33 = 200 pC/N, εr = 1322, TC = 115 ℃, respectively.