Insulator–metal transitions induced by electric and magnetic fields, in thin films of charge-ordered Pr1−Ca MnO3

Thin films of charge-ordered manganates, Pr1−x Ca x MnO3 (x=0.3,0.4) are shown to undergo electric current-induced insulator–metal (I–M) transitions, the transition temperature increasing with the current. The occurrence of I–M transitions in these films without prior laser irradiation is noteworthy. The films show interesting memory effects and some non-linearity in the I–V characteristics. The magnetic-field induced I–M transition in the films is independent of the current employed. At low magnetic fields, or at low currents, resistance oscillations occur due to temporal fluctuations between resistive states.