中文摘要：

为开发新型电阻负温度系数（negative temperature coefficient,NTC）热敏陶瓷材料,采用湿化学法制备Ga掺杂ZnO（GZO）陶瓷Zn1-xGaxO（x分别为0.005,0.01,0.02,0.03,0.04和0.05）.利用X射线衍射分析材料的相组成,用扫描电镜观察陶瓷的微观结构,通过电阻-温度曲线和交流阻抗谱研究GZO陶瓷的电子导电性和温度敏感特性.结果表明,GZO陶瓷材料具有六方纤锌矿晶体结构;Ga掺杂能明显改善ZnO的电子导电性,GZO陶瓷的电阻率随温度升高呈指数关系降低,呈现优异的NTC特性.Zn1-xGaxO陶瓷的NTC材料常数为4196~5975 K.其电子导电性和NTC性质由呈现半导体性质的晶粒效应和热激活导电的晶界效应共同贡献.

英文摘要：

In order to explore a new type of thermal sensitive ceramics with the negative temperature coefficient （NTC） of resistance, the Ga-doped ZnO（GZO） ceramics Znl-xGaxO（x is 0.005, 0.01, 0.02, 0.03, 0.04 and 0.05） were prepared by using a wet-chemical synthesis method. The phase component of the prepared ceramics was analyzed by X-ray diffractometer and the microstructures were observed by scanning electron microscopy. The electrical conductivity and thermal sensitivity of the GZO ceramics were investigated by using resistance-temperature measurement and AC impedance analysis. The results show that all the ceramics have wurtzite type hexagonal crystal structure, and Ga-doping can obviously improve the electrical conductivity of ZnO. The resistivity of GZO ceramics decreases with increasing the temperature. The GZO ceramics have excellent feature of NTC of resistivity with the materials constants ranging from 4 196 K to 5 975 K for various Ga-contents. The electrical conductivity and NTC characteristics of the GZO ceramics are proposed to result from the grain effect （bulk effect） presenting semiconductive feature and grain-boundary effect from thermally activated conduction.