Resistive Switching Mechanism in ZnxCd1 − xS Nonvolatile Memory Devices

Nonvolatile information storage devices based on an abrupt resistance switch when an electric bias is applied are very attractive for future memory applications. Recently, such a resistance switch was described in ferroelectric Zn_xCd_1-xS, but the mechanism of switching remains controversial. Here, we present results that elucidate the mechanism, showing that a metal needs to be easily oxidized and is capable of diffusing into the ZnCdS film as a cation impurity forming a filamentary metallic conduction path