Transport properties and photo-induced effect in La0.82Te0.18MnO3 thin film

The transition from the metallic phase to the nonconductive phase occurred at 283 K in La0.82Te0.18 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(Delta rho/rho(0)) 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.