Sm对BaTiO_3陶瓷的气相扩渗及其电性能  

Gas penetration of Sm into BaTiO_3ceramics and their electric characteristics

作　　者：郝素娥[1] 韦永德[1] 

机构地区：[1]哈尔滨工业大学理学院应用化学系,黑龙江哈尔滨150001

出　　处：《材料科学与工艺》2004年第3期258-260,264,共4页Materials Science and Technology

基　　金：黑龙江省重点攻关资助项目(GB02A301).

摘　　要：为了改善BaTiO3陶瓷的电性能,采用气相法对BaTiO3陶瓷扩渗了Sm元素,探讨了Sm扩渗对BaTiO3陶瓷导电性能和介电性能的影响.研究表明:经Sm扩渗后,BaTiO3陶瓷的室温电阻率从4 3×109Ω·m下降到2 1×102Ω·m,而且随着频率增大和温度升高,交流电导逐渐增大,BaTiO3陶瓷的导电性更强;经Sm扩渗的BaTiO3陶瓷的晶粒电阻随着温度的变化,呈现PTC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一致,试样总电阻的PTC效应已不存在,有向导电体过渡的趋势;Sm扩渗使BaTiO3陶瓷的介电常数在低频下显著增加,介电常数随温度的变化呈明显的PTC效应,并使BaTiO3陶瓷的居里温度升高到128 9oC.In order to improve the electric characteristics of BaTiO_3 ceramics, the penetration of Sm element into BaTiO_3 ceramics in gas state and the effects on electric characteristics of BaTiO_3 ceramics were studied. The results show that the penetration of Sm element makes the electric characteristics of BaTiO_3 ceramics chang obviously. The resistivity of Sm-penetration BaTiO_3 ceramics decreases obviously, when the Sm element content is 0.002, the penetration temperature is 860 ℃ and the penetration time is 4 h, the resistivity decreases to the smallest, which changes from 4.3×10~9 Ω·m to 2.1×10~2 Ω·m, and the conductance increases with the increase in frequency and temperature, the electrical conductivity becomes better. The grain resistance of Sm-penetration BaTiO_3 ceramics exhibits PTC effect, but the grain boundary resistance decreases continuously with the increase in temperature. The regularity of the total resistance is similar to the grain boundary resistance, the PTC effect is nonexistence, and is inclined to change to conductor. The dielectric constant (ε) of Sm-penetration BaTiO_3 ceramics increases visibly at lower frequency. The dielectric constant exhibits PTC effect,and the Curie-temperature (T_c) has gone up to 128.9 ℃.

关 键 词：钐 稀土 钛酸钡陶瓷 气相扩渗 电性能 

分 类 号：TQ174[化学工程—陶瓷工业] O614.33[化学工程—硅酸盐工业]