摘要
利用透射电子显微镜及其电子衍射和X射线能谱分析,高分辨电子显微镜及其微区电子衍射,以及离子探针,证实了低温一次烧结的SrTiO_3陶瓷晶界层电容器材料其晶界绝缘层的形成是由于受主性杂质Li_2O的晶界偏析造成的,并且进一步分析了引起离子偏析的条件和机理。发现只有在施主掺杂和还原气氛烧结的情况下才存在Li_2O的晶界偏析现象。这是因为由施主杂质进入晶格和还原烧结气氛而增强的晶格氧挥发是引起Li_2O晶界偏析的根本原因。
By use of TEM and its electron diffraction and X-ray energy dispersive spectrum, HREM and its microzone electron diffraction, and second ion mass spectrum (SIMS), it has been proved that the formation of the insulating grain boundary of the low-temperature, single-step sintered SrTiO_3 grain boundary barrier layer (GBBL) capacitors is caused by the grain boundary segregation of acceptor impurity Li_2O, and the condition and mechanism of Li_2O grain boundary segregation are analyzed. It is found that exists Li_2O grain boundary segregation only in the circumstance of donor doping and reducing atmosphere sintering. This is because the volatilization of oxygen promoted by the incorporation of donor dopant into lattice and reducing sintering atmosphere is the essential factor of Li_2O grain boundary segregation.
出处
《中国科学院研究生院学报》
CAS
CSCD
1993年第4期368-374,共7页
Journal of the Graduate School of the Chinese Academy of Sciences
关键词
SrTiO3陶瓷
晶界层电容器
低温烧结
SrTiO_3 ceramics
GBBL capacitors
low-temperature sintering
ion segregation
volatilization of oxygen
