摘要
To investigate the multi-functional ceramics with both high permitivity and large nonlinear cofficient,we have prepared rare-earth Tb-and-Co doped ZnO and TO_(2)rich CaCu_(3)Ti_(4)O_(12)(TCCTO)powders by chemical co-precipitation and sol-gel methods re-spectively,and then obtained the TCCTO/ZnO composite ceramics,sintered at 1100℃for 3h in air.Analyzing the composite ceramics of the microstructure and phase composition indicated that the composite ceramics were composed of the main phases of ZnO and CaCu_(3)Ti_(4)O_(12)(CCTO).Our results revealed that the TCCTO/ZnO composite ceramics showed both high dielectric and good nonlinear electrical behaviors.The composite ceramic of TCCTO:ZnO=0.3 exhibited a high dielectric constant of~210(1 kHz)with a nonlinear cofficient of~11.The dielectric behavior of TCCTO/ZnO composite could be explained by the mixture rule.With the high dielectric permittivity and tunable varistor behaviors,the composite ceramics has a potential application for the higher voltage transportation devices.
基金
supported by the Ministry of Science and Technology of China through a 973-Project under Grant No.2009CB623303
NSF of China(50737001,50972068)
NSF of Beijing 2092016
Scientific Research Project of Tsinghua University No.2009THZ08063.
