Nb掺杂对BaTi0.96Al0.04O3陶瓷介电性能的影响

摘要

The BaAl0.04Ti0.96-xNbxO3 (0≤x≤0.08) ceramics were prepared by solid state reaction method. The structure, dielectric properties and doping mechanism of BaTiO3 ceramics co-doped with Al-Nb were investigated by XRD, LCR analyser and Gulp software. The results reveal that when x≥0.03, a second phase appears in the ceramic samples. With the increasing of Nb5+doping content, the BaTiO3 ceramics transform from traditional ferroelectrics to relaxation ferroelectrics, the dielectric peak temperature (Tm) shifts to low temperature, the dielectric constant increases when x≤0.01, while it decreases when x≥0.02. Barium vacancy compensation mechanism occurs preferentially and a small amount of titanium vacancy compensation mechanism exists by the Gulp code calculation analysis. Defect dipoles in the crystal mainly are [2NbTi - V"Ba].%为探究Al-Nb共掺对BaTiO3介电性能的影响及其掺杂机制，以BaTi0.96Al0.04O3为基础配方，通过传统的固相反应法制得BaAl0.04Ti0.96-xNbxO3(0≤x≤0.08)陶瓷样品，并通过XRD、LCR分析仪和Gulp软件来对样品的结构、介电性能进行分析。结果表明：当x≥0.03时陶瓷样品中出现第二相；随着Nb5+含量的增加，陶瓷从传统的铁电体转变成弛豫铁电体，介电峰值温度（Tm）向低温方向移动，且当 x≤0.01时介电常数增大，当x≥0.02时介电常数减小；通过Gulp模拟分析得出晶体中钡空位补偿机制优先发生，可能伴有少量钛空位补偿，主要存在的缺陷簇是。•Ti Baé2Nb - V¢ùëû