title: Nanoscale magnetization reversal caused by electric field-induced ion migration and redistribution in cobalt ferrite thin films.
abstract: Reversible nanoscale magnetization reversal controlled merely by electric fields is still challenging at the moment. In this report, first-principles calculation indicates that electric field-induced magnetization reversal can be achieved by the appearance of unidirectional magnetic anisotropy along the (110) direction in Fe-deficient cobalt ferrite (CoFe(2-x)O4, CFO), as a result of the migration and local redistribution of the Co(2+) ions adjacent to the B-site Fe vacancies. In good agreement with the theoretical model, we experimentally observed that in the CFO thin films the nanoscale magnetization can be reversibly and nonvolatilely reversed at room temperature via an electrical ion-manipulation approach, wherein the application of electric fields with appropriate polarity and amplitude can modulate the size of magnetic domains with different magnetizations up to 70%. With the low power consumption (subpicojoule) characteristics and the elimination of external magnetic field, the observed electric field-induced magnetization reversal can be used for the construction of energy-efficient spintronic devices, e.g., low-power electric-write and magnetic-read memories.
authors: Xinxin
authors: X
authors: Chen
authors: Xiaojian
authors: X
authors: Zhu
authors: ‡Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore.
authors: Wen
authors: W
authors: Xiao
authors: Gang
authors: G
authors: Liu
authors: §Department of Physics, National University of Singapore, 117542, Singapore.
authors: Yuan Ping
authors: YP
authors: Feng
authors: ‡Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore.
authors: Jun
authors: J
authors: Ding
authors: Run-Wei
authors: RW
authors: Li
keywords: cobalt ferrite thin films; electric field control of magnetism; ion migration and redistribution; reversible magnetization reversal