Electrically programmable magnetoresistance in AlO x -based magnetic tunnel junctions

Abstract

We report spin-dependent transport properties and I–V hysteresis characteristics in an AlO x-based magnetic tunnel junction (MTJ). The bipolar resistive switching and the magnetoresistances measured at high resistance state (HRS) and low resistance state (LRS) yield four distinctive resistive states in a single device. The temperature dependence of resistance at LRS suggests that the resistive switching is not triggered by the metal filaments within the AlO x layer. The role played by oxygen vacancies in AlO x is the key to determine the resistive state. Our study reveals the possibility of controlling the multiple resistive states in a single AlO x-based MTJ by the interplay of both electric and magnetic fields, thus providing potential applications for future multi-bit memory devices.