Switching behavior of oxygen-deficient La0.6Ca0.4MnO3-δ thin films

Photoinduced switching of resistance by several orders of magnitude is observed in oxygen-deficient La0.6Ca0.4MnO3-delta thin films deposited on Si substrates. The magnitude of the transient photoconductivity could attain 95.9% at room temperature under 532 nm cw laser illumination at laser intensity of 142 mW/cm(2). The switching has a fast photoresponse effect on a nanosecond time scale when irradiated by a 532 nm laser pulse of 7 ns duration. The photocurrent and photoresponse times depend on the laser intensity and the applied electric field. These results can be important for practical applications in the manganite-based optical devices. (C) 2007 American Institute of Physics.