论文部分内容阅读
Photoinduced effects on the transmission and resistivity in wide-bandwidth manganite La0.7Sr0.3MnO3 films (TC = 350 K) have been investigated at various temperatures in the range of 5-470K by means of the time-resolved pump-probe method. Below TC, we have observed a negative transmission change △TM/TM at 2.54eV and a positive resistivity change △ R/R under photo-irradiation at excited energy Eexc = 3.20 eV. With temperature approaching to TC, the values of △TM/TM and △R/R show a significant reduction. We have ascribed the photoinduced changes on the transmission and resistivity of the La0.7Sr0.3MnO3 film to the charge-ordering fluctuation in the ferromagnetic phase, which is similar to that observed in the narrow-bandwidth La0.7Ca0.3MnO3 films.