Sb掺杂SnO_2基NTC热敏陶瓷的制备与电学特性

Preparation and Electrical Characteristic of Sb-doped SnO_2 Based NTC Thermistors

采用湿化学法制备了锑掺杂氧化锡Sn1-xSbxO2-δ(ATO,x=0.003、0.005、0.007和0.01)粉体材料,并以Li2O-TiO2为助烧剂,用传统烧结工艺制得ATO陶瓷。利用X射线衍射分析了材料的相组成,扫描电子显微镜观察陶瓷的微观结构,通过电阻-温度特性测试仪和交流阻抗谱研究了ATO陶瓷导电性随温度的变化。结果表明,ATO材料具有四方晶体结构;1200℃烧结获得致密度为95%以上的陶瓷试样。该陶瓷材料呈现典型的电阻负温度系数效应。利用能带理论和电子跃迁模型讨论了ATO陶瓷的导电机理。

Sn1-xSbxO2-δ（ATO,x=0.003、0.005、0.007 and 0.01） powders were prepared by a wet-chemical synthesis process,and the corresponding ceramics were obtained by the conventional sintering technique with Li2O-TiO2 as the sintering additive.The phase component of the prepared materials was analyzed by using X-ray diffractometry and the ceramic microstructures were observed by scanning electron microscopy.The temperature dependence of resistivity of the ATO ceramics was investigated with the resistance-temperature measurement system and AC impedance analysis.The results show that the ceramics with a relative density of higher than 95% can be obtained by sintering at 1200℃,and the ceramics have a tetragonal crystal structure and show a typical effect of negative temperature coefficient of resistivity.The conduction mechanisms of the ATO ceramics were discussed by using energy band theory and electron hopping model.