Microstructure and dielectric properties of (Ba1-xCax)z(Ti0.99-yZryMn0.01)O3 (BCTZM) with various cation ratios (A/B) sintered in reducing atmosphere and then annealed to reoxidize the ceramic bodies were investigated. With decreasing A/B cation ratio, concurrent with the grain size reduction, the insulation resistance and lifetime of the BCTZM are both increased. The degradation of insulation resistance is closely related to oxygen partial pressure used during annealing and the resulting microstructure of the ceramics. Within the same volume, the specimen with fine grain size provides more grain boundaries, in comparison to large grain size specimens, which helps in providing an efficient diffusion pathway for oxygen during annealing. The result of oxidation of the Mn, that is, a change in the valence state of Mn from Mn+2 to Mn+3 is confirmed from thermogravimetric analysis and electron paramagnetic resonance analysis.
|頁（從 - 到）||157-162|
|期刊||Journal of Materials Science: Materials in Electronics|
|出版狀態||Published - 2000|
All Science Journal Classification (ASJC) codes