摘要
研究了热历史对四方相钛酸钡陶瓷弛豫性质的影响。结果表明,不同热历史的钛酸钡试样在四方相温区都出现弛豫内耗峰,但不同热历史的试样具有不同性质的弛豫过程。从立方相降温测得的四方相陶瓷的弛豫激活能为0.61 eV;而从单斜相升温测得的四方相陶瓷的弛豫激活能为1.12 eV,相差几近一倍。用氧缺位的分布和弛豫热力学选择定则提出了四方相的弛豫机理,计算了不同热处理后处于不同对称位置氧缺位的浓度。
The influence of heat-history on relaxation is studied for barium titanate ceramics. The results indicate that an internal friction relaxation peak is observed in tetragonal barium titanate with different heat-history, however, having different relaxation characteristics. The activation energy is 0. 61 eV for the sample descending from cubic phase, while for the sample ascending from orthorhombic phase it nearly doubles and becomes 1.12 eV. Based on the oxygen vacancy distribution and relaxation thermodynamics, the relaxation mechanism is proposed. At the same time oxygen vacancy concentrations on different sites （a, b and c sites） in tetragonal barium titanate, with different heat treatments, are calculated.
出处
《物理学进展》
CSCD
北大核心
2006年第3期289-295,共7页
Progress In Physics
基金
NSFC19974077
10027001和10004017的资助
