Current-Induced Reversible Resistance Jumps in La0.8Ca0.2MnO3 Microbridge

Two spatially confined La0.8Ca0.2MnO3（LCMO） microbridges with different widths, starting from a single LCMO fihn （3mm×5 mm）, are fabricated by optical lithography. A second new and robust metal-insulator transition （MIT） peak at about 75K appears, in addition to the normal MIT at 180 K observed in the standard LCMO film. When the two bridges are processed by currents of high densities, interesting reversible resistance jumps are excited only around the new peak. A stronger dependence of resistance jump on current excitation is found for the bridge with a smaller width. The temperature driven transition between new excited multiple metastable states are involved to explain the interesting low-temperature ultra-sharp jumps.