Influence of thermal treatments on the low frequency conductivity and microwave dielectric loss of CaTiO3 ceramics

✍ Scribed by Peng Hu; Huan Jiao; Chun-Hai Wang; Xiao-Ming Wang; Shi Ye; Xi-Ping Jing; Fei Zhao; Zhen-Xin Yue

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 560 KB
• Volume: 176
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2010.12.010

✦ Synopsis

We prepared CaTiO 3 by solid state reactions as a model for Ti-based microwave dielectric ceramics to investigate the influence of thermal treatment on conductivity and microwave dielectric loss. The intrinsic defect concentrations of CaTiO 3 may be modified by air-quenching, air-annealing and thermal treatment in various atmospheres such as O 2 , Ar and air. CaTiO 3 has p-type conductance implying that calcium vacancy V × Ca may be the dominant defect. The variation in defect concentration influences the low frequency conductivity but not the microwave dielectric loss. The V × Ca concentration in the air-quenched sample was found to be lower than that in the air-annealed one. However, the former showed ∼8% deterioration and the latter showed a 14% improvement in the Q × f value. The data, therefore, suggests that other factors such as thermally induced strain rather than intrinsic defects may influence the microwave dielectric loss.