高分子辅助化学溶液沉积法制备La0.7Sr0.3MnO3/Si薄膜及电磁输运研究

利用高分子辅助化学溶液沉积法在Si(100)衬底上外延生长La0.7Sr0.3MnO3薄膜.并利用X射线衍射仪结果、扫描电子显微镜结果和电阻率-温度曲线(ρ-T曲线)结果、磁电阻(MR)曲线结果对其晶体结构、表面形貌和电磁输运机制进行了研究.结果显示实验制备的La0.7Sr0.3MnO3薄膜为赝立方钙钛矿多晶结构,薄膜表面均匀平滑,结晶性好,晶粒尺寸约为50~70 nm.随着温度降低,薄膜电输运机制从绝缘体行为向转变金属导电行为.金属绝缘转变转变点温度(TMI)随磁场的增加而升高,在0 T和1 T分别为TMI=238K、246 K.电输运测试结果说明,低温(TTMI)时薄膜按照绝热近似的小极化子输运.

Transport Properties of La0.7Sr0.3MnO3/Si Thin Films Grown by Polymer-assisted Chemical Solution Deposition

Perovskite man-ganese oxides La0.7Sr0.3MnO3 (LSMO) thin films were epitaxial growth on Si(100) substrates by the polymer-assisted chemical solution deposition (PACSD) method.Microstructure, surface morphology and electronic transport behavior were investigated by X-ray diffraction (XRD) spectra, scanning electron microscope (SEM), ρ-T curves and magnetoresistance (MR) of LSMO thin films.The surface of the LSMO thin films was smooth without crack.The LSMO thin films have a polycrystalline structure, and the grain size is about 50-70 nm.Metal-insulator transitions were observed in the samples.The transition temperature were 238 K and 246 K for 0 T and 1 T, respectively.The result of transport property suggested that the electron-electron scattering becomes dominant below the transition temperature, while the film has small polarons behavior of the adiabatic approximation above the transition temperature.