Modulating the transport property of flexible La0.67Ca0.33MnO3 thin film by mechanical bending

Abstract

Flexible epitaxial La0.67Ca0.33MnO3 (LCMO) thin films are fabricated on an SrTiO3 buffered (001)-oriented fluorophlogopite substrate. The metal-to-insulator transition tends toward lower temperature when subjected to mechanical bending. Moreover, the transport behavior of the bent LCMO films in the insulating region follows the variable range hopping model and the resistivity increases with the reduction in the bending curvature radii because the applied strain aggravates the distortion of the LCMO crystal structure, decreases the hopping distance, and, hence, impedes the transport of charge carriers. The resistivity change induced by the mechanical bending can go up to 104% at 100 K and 105% at 10 K. Such a large resistivity change makes the flexible LCMO thin film promising as a mechanical-bending switch device at low temperature.