The action spectra for the photoinduced insulator-metal transition in Pr1-xCaxMnO3 were investigated in the 0.45-3.05eV range. The photon-density threshold for the transition exhibits a gaplike behavior a∼0.4eV with anisotropic features, and it is insensitive to the degree of carrier doping x. A two-stage mechanism is proposed for the transition. In the first stage, photoexcited charge carriers melt down the charge-ordered state by screening effects, which is followed by a local formation of metastable metallic domains. In the second stage, the barrier between the metallic domains is overcome by an applied electric field resulting in a continuous conducting path that remains stable as long as the current is maintained.
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jan 1 1999|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics