We report spin-dependent transport properties and I-V hysteresis characteristics in an AlOx-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 AlOx layer. The role played by oxygen vacancies in AlOx is the key to determine the resistive state. Our study reveals the possibility of controlling the multiple resistive states in a single AlOx-based MTJ by the interplay of both electric and magnetic fields, thus providing potential applications for future multi-bit memory devices.
