STABILITY OF A PHOTOINDUCED INSULATOR-METAL TRANSITION IN PR1-XCAXMNO3

A photoinduced insulator-metal transition has been found in crystals o f Pr1-xCaxMnO3 with various doping levels (x = 0.31, 0.35, 0.40, 0.45, and 0.50). The current-voltage relationship and the temperature depen dence of the stability of the metallic region indicate that the metall ic states of all x are of the same origin, and exclude the Joule heati ng as the mechanism of sustaining the metallic phase. The driving forc e for the transition is clearly the collapse of the charge-ordered sta te by the photocarriers.