Voltage-current hysteretic characteristics in ME/Nd0.7Ca 0.3 MnO3 thin films with ME = Au, Pt, Ag, Cu

In this work, different metal electrodes (ME) are sputtered on the surface of Nd0.7Ca0.3MnO3 thin films. The behavior of current-voltage (I-V) characteristics of these films is investigated. Among different metal electrodes, Au yields the smallest electrical hysteresis loop, while Cu generates the largest one. According to our analysis on the work function of each ME material, the result of ME-dependent I-V hysteresis loop can not be simply explained by the Schottky barrier. We propose that the electronnegativity of each ME material also plays a crucial role for the oxygen diffusion at interface. In conclusion, this study provides useful information for understanding the origin of I-V hysteresis loop and the principle of resistance switching in CMR manganites. © 2007 IEEE.