稀土气相扩渗BaTiO_3基PTC陶瓷的NTCR效应  

NTCR Effect of BaTiO_3-based PTC Ceramics Penetrated by Rare Earth

作　　者：郝素娥[1] 孙亮[1] 黄金祥[1] 韦永德[1] 

机构地区：[1]哈尔滨工业大学应用化学系,哈尔滨150001

出　　处：《高等学校化学学报》2005年第12期2207-2210,共4页Chemical Journal of Chinese Universities

基　　金：黑龙江省重点攻关项目(批准号:GB02A301)资助

摘　　要：采用稀土气相扩渗法制备了La改性的BaTiO3基PTC陶瓷,并对其室温电阻率的变化及温-阻效应进行了研究. 结果表明, BaTiO3基PTC陶瓷经La气相扩渗后, 室温电阻率从2.7×109 Ω·m下降到220 Ω·m, 在25～500 ℃范围内, 电阻率随温度升高单调递减, 从220 Ω·m降至5.8 Ω·m, 产生了明显的NTCR效应. 结合XRD, SEM, EDAX以及介电性能测试结果分析了La气相扩渗BaTiO3基PTC陶瓷NTCR效应的形成机理, 建立了NTCR效应的物理结构模型.The modified BaTiO3-based PTC ceramics were prepared by gaseous penetration of rare earth La, and the change laws of the resistivity at room temperature and the temperature-resistivity properties were studied. The experimental results show that the modified BaTiO3-based PTC ceramics after La penetration have a significant decrease in resistivity at room temperature, which decreases from 2.7×10^9 to 220Ω· m, and the resistivity decreases progressively from 220 to 5.8Ω· min the temperatures range from 25℃ to 500℃, which indicates a significant NTCR effect. Through analyses of XRD, SEM, EDAX and the dielectric properties of the BaTiO3-based PTC ceramics penetrated by La, the forming mechanism of the NTCR effect was explored, and the physical structure model of the NTCR effect was established.

关 键 词：稀土 气相扩渗 NTCR效应 钛酸钡陶瓷 

分 类 号：O614[理学—无机化学]