Low current induced electroresistance in the polycrystalline La0.6Pb0.4MnO3 thin films

Abstract

We report the temperature and current dependence of electroresistance (ER) in the polycrystalline (PC) La0.6Pb0.4MnO3 (LPMO) thin films with grain size 55 nm. ER is observed only below metal-insulator transition temperature (TIM). In the temperature range T<TIM, ER shows a sharp increase at low currents (<50 μA) followed by saturation. The experimental results can be understood in terms of modification of grain boundaries characteristics by spin polarized carriers. ER versus current behavior remains unaffected by the magnetic field, indicating that the mechanism governing ER and magnetoresistance are effectively decoupled. The sharp increase in ER at low currents suggests that PC LPMO films may have potential for application in low power devices operating at low temperatures.