TKU Spintronics Lab

淡江物理自旋電子學實驗室

Research

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 AlOx the 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. 

Low-frequency 1/f voltage noise has been employed to probe stochastic charge dynamics in AlOx-based non-volatile resistive memory devices exhibiting both resistive switching (RS) and magneto-resistive (MR) effects. A 1/fγ noise power spectral density is observed in a wide range of applied voltage biases. By analyzing the experimental data within the framework of Hooge’s empirical relation, we found that the Hooge’s parameter α and the exponent γ exhibit a distinct variation upon the resistance transition from the low resistance state (LRS) to the high resistance state (HRS), providing strong evidence that the electron trapping/de-trapping process, along with the electric field-driven oxygen vacancy migration in the AlOx barrier, plays an essential role in the charge transport dynamics of AlOx-based RS memory devices. 

Student Honor roll

2023


2022

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2021

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2020

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2019

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2018