Room-temperature electric control of exchange bias effect in CoO1 – δ/Co films using Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (110) substrates*

Abstract

Significant electric control of exchange bias effect in a simple CoO1–δ /Co system, grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (110) (PMN-PT) substrates, is achieved at room temperature. Obvious changes in both the coercivity field (H C) and the exchange bias field (H E), of 31% and 5%, respectively, have been observed when the electric field is applied to the substrate. While the change of coercivity is related to the enhanced uniaxial anisotropy in the ferromagnetic layer, the change of the exchange bias field can only originate from the spin reorientation in the antiferromagnetic CoO1–δ layer caused by the strain-induced magnetoelastic effect. A large H E/H C > 2, and H E ∼ 110 Oe at room temperature, as well as the low-energy fabrication of this system, make it a practical system for spintronic device applications.