Photo-induced conductivity in La2/3(Ca1–xSrx)1/3MnO3 (x = 0, 1/3, 2/3) films

The photo-induced resistance change has been observed in the La2/3(Ca1–xSrx)1/3MnO3 films with x = 0, 1/3 and 2/3 prepared by RF magnetron sputtering on the LaAlO3 substrate. The photo-induced relative change in resistance increases initially with increasing temperature, followed by a decrease. The maximum values of the relative change in resistance decrease from 43.5 to 27.2% with increasing x, and the corresponding temperatures increase from 252 to 317 K. The intriguing mechanism of the photo-induced character and the effect of the Sr content in the perovskite films are discussed.