未掺杂铅酸钡陶瓷的缺陷补偿机理(英文)

DEFECT COMPENSATING MECHANISM IN UNDOPED BARIUM PLUMBATE

用高温平衡电导法研究了未掺杂铅酸钡(BaPbO3)陶瓷的缺陷化学,确定了未掺杂BaPbO3材料的缺陷化学模型,同时,从BaPbO3材料的缺陷结构的角度讨论了热处理气氛对材料室温电导率的影响。BaPbO3材料在实验氧分压范围内呈现p型电导,在高氧分压下,铅离子(Pb4+)空位和空穴占主导,材料表现出本征缺陷行为。在中氧分压下,受主杂质成为主导缺陷,电荷补偿缺陷为空穴。在低氧分压下,受主杂质的电荷补偿缺陷转变为氧离子空位,还原反应成为电荷补偿缺陷的主要来源。材料室温电导率的变化完全是由于在不同的氧分压环境下材料中主导缺陷的转变和缺陷浓度的变化而引起的。

Defect chemistry of undoped barium plumbate （BaPbO3） was determined by the measurement of the equilibrium electrical conductivity vs oxygen pressure （10^-12-10^5 Pa）. A defect model for undoped BaPbO3, which emphasized the role of impurities, is presented. Based on the defect model of BaPbO3, the influence of defect chemistry on room-temperature conductivity is discussed. The BaPbO3 is a species of p-type conductor in the experimental oxygen pressure range. At highly oxygen pressure the condition of charge neutrality is dominated by the lead vacancies and their compensating holes. In the midrange of oxygen pressure, the acceptor impurities become the dominant source of defects and the charge compensating defects are holes. At a lower oxygen pressure, the compensating defects of acceptor impurities change into oxygen vacancies and the reducing reaction becomes the dominant source of compensating defects. The room-temperature conductivity of undoped BaPbO3 is controlled by the major defects and the concentration of them.