Correlation between degree of crystallinity and transition field in electric or magnetic field-induced insulator-metal transition of Pr_(0.5)Ca_(0.5)MnO_3 thin films

摘要

Degree of crystallinity (DOC) effect onto electric and magnetic field-induced insulator-metal (IM) transition of Pr_(0.5)Ca_(0.5)MnO_3 (PCMO) thin films was studied. The films with various DOC were prepared by a pulsed laser deposition method, varying the substrate materials (single crystalline MgO or amorphous SiO_2) and the deposition temperature (600 or 750℃). Planer-type junctions were fabricated with these films for the observation of IM transition. In electric field-induced IM transition, there was a tendency that the films with lower DOC show lower transition field. In the magnetic field, on the other hand, the film of higher DOC showed an IM transition under lower field, in contrast to the case of the electric field.