(La_(0.7)Sr_(0.3)MnO_3)_m(BiFeO_3)_n超晶格结构的导电机理

Conduction mechanisms in (La_(0.7)Sr_(0.3)MnO_3)_m(BiFeO_3)_n superlattice

利用射频磁控溅射的方法在SrTiO3(001)基片上制备了(La0.7Sr0.3MnO3)m(BiFeO3)n超晶格结构.对所制备的超晶格结构进行了50—150℃温度范围内的电流-电压测试分析.结果表明,随着BiFeO3薄膜的厚度减小,温度的升高,(La0.7Sr0.3MnO3)m(BiFeO3)n超晶格结构的电流变大.进一步根据介质导电模型对(La0.7Sr0.3MnO3)m(BiFeO3)n超晶格结构的导电特性做了分析.在温度较低或者电场较弱时,所制备的(La0.7Sr0.3MnO3)m(BiFeO3)n超晶格结构表现为欧姆导电,而在高温,高电场的情况下,其导电行为由空间电荷限制电流机理主导.

（La0.7 Sr0.3 MnO3 ）m （ BiFeO3 ）n superlattices were grown in situ on SrTiO3 （ 001 ） substrates by rf magnetron sputtering. The current-voltage measurements were performed under the temperature of 50—150℃ for the superlattices specimens. The analysis showed that the leakage current increased with increasing the temperature or decreasing the BFO thickness in the samples. And the conduction mechanisms of the prepared （ La0. 7 Sr0. 3 MnO3 ） m （ BiFeO3 ） n superlattices were analyzed according to common insulator conduction models. It exhibited that the space-charge-limited current were dominated in the as fabricated （La0. 7 Sr0. 3 MnO3 ） m（BiFeO3 ） n superlattices in high temperature or high electrical field.