BaPbO_3与BaTiO_3陶瓷的导电特性比较

Comparison of Conductive Properties Between BaPbO_3 and BaTiO_3 Ceramics

从BaPbO3与BaTiO3多晶态陶瓷的缺陷结构出发,结合不同气氛下烧成试样的室温电导率,探讨两种材料的导电特性与晶体缺陷结构之间的关系,从微观本质上阐述晶体缺陷对材料电学性能的影响.结果表明:BaPbO3与BaTiO3不同的缺陷结构决定了两种材料具有不同的电学性能;BaPbO3材料中受主能级较浅,受主中心所束缚的空穴很容易跃迁至价带形成导电载流子,在氧化气氛下烧成的试样呈高导电性;BaTiO3材料中受主能级较深,氧化气氛下烧成的试样为绝缘体.

In order to investigate the effect of crystal defect on the electrical properties of ceramics in a microcosmic scale, BaPbO3 and BaTiO3 polycrystalline ceramics were used as two objects to investigate the relationship between their conductive properties and crystal defect structures by studying the defect structure and room-temperature conductivity of the ceramics sintered in different firing atmospheres. The results show that the difference in electrical properties between BaPbO3 and BaTiO3 ceramics mainly results from the difference in the defect structure. As the BaPbO3 sample is of a shallow acceptor energy level, high conductivity can be achieved after sintering in oxidizing condition because the cavities trapped in the acceptor center are easy to transit to the valence band to form conductive carriers. However, the BaTiO3 sample with a deep acceptor energy level turns into an insulator after sintering in oxidizing condition.