Electrical conduction properties of La-substituted bismuth titanate single crystals
Electrical conduction properties of La-substituted bismuth titanate single crystals
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发表时间：
2005
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影响因子：
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通讯作者：
Masatake Takahashi;Y. Noguchi;M. Miyayama
中科院分区：
文献类型：
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作者：
Masatake Takahashi;Y. Noguchi;M. Miyayama
采用自熔盐法生长了掺镧钛酸铋单晶，并对其高温电导率进行了研究。La掺杂抑制了退火过程中铋的挥发，降低了a轴和c轴的电导率。结果表明，La的取代稳定了钙钛矿块，从而降低了作为导电载流子的氧空位和空穴的浓度。从头算结果表明，La掺杂提高了钙钛矿块中氧空位的形成能，支持上述实验结果。
Single crystals of lanthanum-substituted bismuth titanate were grown by a self-flux method, and electrical conductivities were investigated at high temperatures. Lanthanum substitution suppressed Bi vaporization during annealing and decreased the electrical conductivity in both the aand c-axes. It is suggested that lanthanum substitution stabilizes the perovskite blocks and hence decreases the concentrations of oxygen vacancies and holes as the conduction carriers. An ab-initio calculation indicated that the formation energy of an oxygen vacancy in the perovskite block is increased by lanthanum substitution, supporting the above experimental results.