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用脉冲激光沉积法制备了非金属Te掺杂的钙钛矿锰氧化物La0·82Te0·18MnO3单晶薄膜.该薄膜从83K升温至373K过程中发生金属-绝缘体相变,转变点温度为283K.其电阻率在TTMI时为小极化子输运.薄膜在低温段连续激光(波长为532nm,40mW)作用下电阻率显著增大,电阻变化率在253K达到最大值51·1%,该变化率远大于相同条件下的空穴掺杂材料;在高温段产生了较小的光电导,电阻变化率小于10%.这些现象主要与激光激励下自旋系统和小极化子的变化有关.La0·82Te0·18MnO3薄膜在激光诱导下具有明显的与自旋相关的弛豫现象.激光开始作用时薄膜电阻率随时间的变化符合指数关系.
A non-metallic Te-doped perovskite manganese oxide La0.82Te0.18MnO3 single crystal film was prepared by pulsed laser deposition.The metal-insulator phase transition occurred at 83K to 373K, the transition temperature was 283K. Its resistivity is in accordance with the electron-electron and electron-magnetic scattering formula at T TMI. The resistivity of the film under the action of continuous laser (wavelength of 532nm, 40mW) , And the rate of change of resistance reaches the maximum of 51.1% at 253K, which is much higher than that of hole-doping materials under the same conditions. Small photoconductivity occurs at high temperature, and the rate of change of resistance is less than 10%. These phenomena are mainly related to the changes of the spin system and the small polaron under laser excitation.La0 · 82Te0 · 18MnO3 thin films have obvious spin-dependent relaxation phenomena under the laser-induced laser.When the laser starts to work, the resistivity of the thin film changes with time Changes in line with the exponential relationship.