采用气相稀土扩渗法制备PbTiO_3基导电陶瓷

Conducting Materials of PbTiO_3 Ceramics Prepared by Gaseous Penetration of Rare Earth

通过对钛酸铅陶瓷气相扩渗稀土元素,制备了导电陶瓷材料。通过X射线衍射、电子探针X射线能谱和扫描电镜测试分析,表明稀土元素La,Ce,Gd,Sm等均已渗入到PbTiO3陶瓷体相中,并生成了新的化合物La5O7NO3,La2C2O2,Gd2O3,La2Ti6O15,SmO和CeTi21O38,并使扩渗后的PbTiO3基陶瓷的导电性能发生了十分显著的变化,其室温电阻率从纯PbTiO3陶瓷的2.0×1010?·m下降为0.2?·m,而且随着温度的变化,晶粒电阻呈现明显的PTCR效应,而晶界电阻随着温度的升高,呈急剧连续降低状态,总电阻的变化规律与晶界电阻的变化相类似,试样总电阻的PTCR效应已不存在,已表现出导电体特征。

New conducting ceramic materials were prepared by gaseous penetration of rare earth into PbTiO3 ceramics. Through XRD, EPMA and SEM analysis, it is confirmed that the gaseous penetration make La, Ce, Gd, Sm enter into PbTiO3 ceramics, and the new compounds of LasO7NO3, La2C2O2, Gd2O3, La2Ti6O15, SmO and CeTi21O38 are formed by the penetration of rare earth in the gaseous state. The formed rare earth PbTiO3 ceramic materials have a significant change in electrical properties. The room temperature resistivity decreases from 2.0 × 10^10 Ω·m to 0.2 Ω·m. The grain resistance exhibits an obvious PTCR effect with temperature. However, the grain boundary resistance decreases rapidly with increase of temperature. The change rule of the total resistance is similar to that of the grain boundary. The PTCR effect disappears and the tendency of transition to a conductive body is manifested.