Electric current-induced giant electroresistance in La_0.36Pr_0.265Ca_0.375MnO₃ thin films

The electroresistance (ER) of La_0.36Pr_0.265Ca_0.375MnO₃ (LPCMO) epitaxial thin film was studied under various dc currents. The current effect was compared for the unpatterned film and patterned microbridge with a width of 50 μm. The value of ER in the unpatterned LPCMO film could reach 0.54 under a 1-mA current, which is much higher than ER under 1 mA for the patterned weak phase-separated La_0.67Ca_0.33MnO₃ and La_0.85Sr_0.15MnO₃ microbridges with 50-μm width. More interestingly, for the patterned LPCMO microbridge, the maximum of ER can reach 0.6 under a small current of 100 μA. The results were explained by considering the coexistence of ferromagnetic metallic phase with the charge-ordered phase, and the variation of the phase separation with electric current.