YAlO3的体色与缺陷平衡的关系

Abstract

利用固相扩散法在1 450℃下制备了YAlO3粉末样品和陶瓷片样品,并在不同温度和不同气氛(air,O2 or N2)下对样品进行退火处理调制了其缺陷浓度.基于漫反射光谱和交流阻抗谱分析了YAlO3样品的体色与其缺陷浓度之间的关系.研究结果表明YAlO3具有p型导电机理,其浅棕色体色是由阳离子空位引起的.在高温和氮气氛下处理该材料其缺陷浓度减少,体色变浅.第一性原理计算结果认为YAlO3中的主要缺陷应该是铝空位VAl×.

Powder and pellet samples of YAlO3 with various defect concentrations were prepared using conventional solid state reactions at 1 450 degrees C, followed by annealing in air, O-2 or N-2 atmospheres at various temperatures. The correlation between the body-color of the samples and the defect equilibria was investigated by diffuse -reflection spectra and AC impedance data. The results indicate that YAlO3 has p -type conduction and its light -brown body -color is caused by the cation vacancies. Annealing YAlO3 at high temperature in N2 atmosphere may reduce the defect concentration and the body-color. By the first -principle calculations, it is proposed that the Al vacancies VAlx may be the dominant defects in YAlO3.