Electric-field control of non-volatile magnetization switching without external-magnetic-field bias in CoFeB/(011)-PMN-0.3PT heterostructures

¹ National Synchrotron Radiation, Laboratory & Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China - Hefei, Anhui 230026, China
² CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China - Hefei, Anhui 230026, China
³ Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science and Technology of China - Hefei, Anhui 230026, China

^(b) yangyuanjun@ustc.edu.cn
^(c) cgao@ustc.edu.cn

Received: 31 August 2014
Accepted: 23 December 2014

Abstract

Electric-field control of non-volatile magnetization switching in the absence of external-magnetic-field bias has been investigated in multiferroic Co₄₀Fe₄₀B₂₀/0.7Pb(Mg_1/3Nb_2/3)-0.3PbTiO₃ (CoFeB/PMN-0.3PT) heterostructure at room temperature. The two non-volatile magnetic states are achieved without magnetic-field bias and can be switched in a reversible and reproducible manner by an electric field. These results are attributed to the modulation of the magnetic anisotropy of the CoFeB layer by as-grown magnetic field and electric-field–induced non-volatile strain through unipolar-electric-field cycling. High-resolution X-ray diffraction studies on the (022) peaks under in situ electric field indicate that the non-volatile strain is closely related to the 71° ferroelastic domain switching ($r1/r2$ to $r3/r4$ ) of the PMN-0.3PT substrate. The corresponding ratio of the ferroelastic domain $r3/r4$ is electrically changed by 14.1% between the two non-volatile magnetic states. Our results provide a promising path to non-magnetically operating magnetic bits by pure electric field at room temperature.