Electric-field-tuned metallic fraction and dynamic percolation in a charge-ordered manganite

A percolative insulator-metal transition triggered by strong electric field is observed in epitaxial thin films of (Pr0.65La0.35)(0.7)Ca0.3MnO3. The field-driven metallic state is achieved in a regime of temperatures where the material is weakly ferromagnetic. Our experiments suggest that the metallic fraction reaches percolation threshold p(c) at a field-dependent temperature T-pc. A strong frequency dependence of complex ac resistance in the vicinity of T-pc is consistent with the picture of percolative transport in a phase-separated medium.