摘要
采用固相法制备了BaTiO3基无铅PTCR陶瓷,通过加入Na0.5Bi0.5TiO3作为移峰剂来提高居里点,同时采用不同方式引入施主掺杂剂Nb2O5来降低室温电阻率。对陶瓷的XRD物相分析、SEM微观形貌分析和PTCR性能测试,结果表明引入Nb2O5方式会对BaTiO3基陶瓷的晶胞参数、微观形貌和室温电阻率产生很大影响。随着Nb2O5摩尔浓度的增加,室温电阻率先迅速减小,然后逐渐增大,而且当Nb2O5摩尔含量为0.2mol%时,室温电阻率最小。掺入0.2mol%Nb2O5和3.0mol%Na0.5Bi0.5TiO3时,BaTiO3基陶瓷的室温电阻率为3830Ω.cm,Tc为142℃,PTC突跳幅度为3个数量级。
Lead free PTCR ceramics based on BaTiO3 were fabricated by a conventional mixed oxide method. The Curie temperature increased with content of Na0.5Bi0.5TiO3, and Nb2O5 introduced by different methods so as to reduce the room temperature resistivity. By the use of X-ray diffraction, scanning electronic and resistivity-temperature measurement instrument, the phase, microstructure and resitivity-temperature dependence were investigated. It shows that doping of Nb2O5 had influences on lattice parameters, microstructure and room temperature resistivity of barium titanate ceramics. The room temperature resistivity first decreased and then increased with improving of the Nb2O5 content, and the minimum of the room temperature resistivity could be obtained when the Nb2O5 content was 0.2mol%. The Bao.97（Bi0.5Na0.5）0.03TiO3-0.002Nb2O5 ceramic exhibited a low ρ RT of 3830Ω·cm, a typical PTCR effect ρ max/ρmin〉10^3 and a Tc of 142℃.
出处
《中国陶瓷》
CAS
CSCD
北大核心
2011年第6期10-13,共4页
China Ceramics
基金
浙江温州科技计划项目(H20100081)
陕西省科技厅工业攻关项目(2010K10-14)
国家自然科学基金项目(51072106)
