自旋零带隙半导体PbPdO₂薄膜结构、电输运特性的磁场调控研究

Magnetic Field Regulation of the Structure and Electrical Transport Properties of Spin-Zero Band-Gap Semiconductor PbPdO₂ Thin Film

采用脉冲激光沉积(PLD)法制备了具有体心正交结构的单相PbPdO2薄膜,且PbPdO2薄膜具有(002)择优取向。根据EDS和XPS的测试结果证实PbPdO2中存在Pb空位和O空位。薄膜中Pb和Pd离子的价态分别为+2和+2价态。另外,PbPdO2的磁性主要和Pb空位诱导出的O1−有关。ρI (T)结果表明在PbPdO2中存在由电流诱导的正庞电致电阻(CER)效应。PbPdO2的金属–绝缘体转变温度(TMI)会随着电流和磁场的增大而增大,这表明了大的电流和磁场都可以推动薄膜的TMI向更高温区转移。最后,以薄膜中的Pb空位为中心,建立了内电场模型,很好地解释了PbPdO2的正CER效应。Single-phase PbPdO2 thin film with body-centered orthogonal structure have been prepared by pulsed laser deposition (PLD), and the PbPdO2 thin film has a (002) preferred orientation. The results of EDS and XPS confirmed the existence of Pb vacancy and O vacancy in PbPdO2 thin film. The valence states of Pb and Pd ions in the film are +2 and +2, respectively. In addition, the magnetism of PbPdO2 is mainly related to O1− induced by Pb vacancy. The ρI (T) results show that there is a positive current-induced CER effect in PbPdO2 thin film. The metal-insulator transition temperature (TMI) of PbPdO2 increases with the increase of the current and magnetic field, which indicates that large current and magnetic field can promote the TMI transfer of the film to a higher temperature region. Finally, an internal electric field model centered on the Pb vacancy in the film is established to explain the positive CER effect of PbPdO2.