摘要
采用交流阻抗谱技术对微波介质材料BaEu2Ti4O12进行了表征。分析了lgε/lgf,Z″/Z'和Y'/lgf等图谱的特征与材料性能的关系.研究结果表明:1)阻抗谱测试得到的介电常数与所发表的微波测试结果有很好的一致性,高频下得到的介电常数实际上是晶粒和晶界的净结果,高质量烧结的材料应具有薄的晶界,因而应表现出较大的介电常数;2)如果将材料从高温下缓慢降温或在O2气氛中退火,材料的导电性都会下降,其原因可以理解为这样处理的材料氧空位浓度降低,进而可以推测这有利于降低材料的介电损失.
The electrical properties of BaEu2Ti4O12 were characterized by meansof AC impedance spectroscopy in the frequency rang of 10-1～107 Hz.The experiment results indicate: (i) the permittivity value measured in this low frequency range is compatible with the published value measured in microwave range.The permittivity value obtained in high frequency range is net effect of bulk and grain boundary permittivitis; better sintered ceramic has thinner grain boundary and may have larger permittivity value;(ii)when the sample was cooled down slowly from elevated temperature or annealed in O2 rich atmosphere,the conductivitywas reduced,which may be explained by the reduction of oxygen vacancies in crystal.These treatments may lower the dielectric loss in microwave range.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2003年第2期109-114,共6页
Acta Physico-Chimica Sinica
