【摘要】 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T<TMI时符合电子-电子、电子-磁振子散射公式;在T>TMI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.更多还原

【Abstract】 The transition from the metallic phase to the nonconductive phase occurred at 283 K in La 0.82 Te 0.18 MnO₃ thin film prepared by pulse laser deposition method. The transport results show that the data satisfy the formula of electro-electro and electro-magnon scattering for T<T MI ; when T>T MI it agrees with small polaron transport model. The effect of the continuous wave laser（532 nm,40 mW） on the film was also investigated. Below T MI , the resistivity has a photo_induced increase. The maximum rate of resistivity changes（Δρ/ρ₀） can reach 51.1%, which is much greater than that of hole-doped manganites. Above T MI there is a photoconduction. The relaxation was observed in the experiment when the laser was turned on and off. The resistively is exponentially related with the time.更多还原