Colossal electroresistance effect at metal elect rode/La_(1-x)Sr_(1+x)MnO_4 interfaces

摘要

We have studied the current-voltage (Ⅰ-Ⅴ) characteristics and resistance switching at the interface between metal electrodes M (=Pt, Au, Ag, Al, Ti, and Mg) and atomically flat cleaved (001) surfaces of La_(1-x)Sr_(1+x)MnO_4 (x=0-1.0) single crystals by using a three-probe method. Hysteretic Ⅰ-Ⅴ characteristics, indicating the appearance of the resistance switching, were observed in the junctions for M=Mg, Al, and Ti, which have relatively shallow work functions. The resistance switching ratio depends on the hole doping x and the optimal doping level is around x=0.5, verifying that the resistance switching property can be controlled by the doping level.