title: Manipulation of magnetization switching and tunnel magnetoresistance via temperature and voltage control.
abstract: Magnetization switching between parallel and antiparallel alignments of two magnetic layers in magnetic tunnel junctions (MTJs) is conventionally controlled either by an external magnetic field or by an electric current. Here, we report that the manipulation of magnetization switching and tunnel magnetoresistance (TMR) in perpendicularly magnetized CoFeB/MgO/CoFeB MTJs can be achieved by both temperature and voltage. At a certain range of temperature, coercivity crossover between top and bottom magnetic layers is observed in which the TMR ratio of the MTJs is almost unmeasurable. Furthermore, the temperature range can be tuned reversibly by an electric voltage. Magnetization switching driven by the voltage reveals an unconventional phenomenon such that the voltage driven coercivity changes with temperature are quite different for top and bottom CoFeB layers. A model based on thermally-assisted domain nucleation and propagation is developed to explain the frequency and temperature dependence of coercivity. The present results of controlling the magnetization switching by temperature and voltage may provide an alternative route for novel applications of MTJs based spintronic devices.
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Houfang
authors.initials: H
authors.lastname: Liu
authors.affiliation: SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Guo
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Zhenchao
authors.initials: Z
authors.lastname: Wen
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Feng
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Wei
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Han
authors.affiliation: SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ji
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Shufeng
authors.initials: S
authors.lastname: Zhang