Electric control of magnetic properties in epitaxially grown FeRh/MgO/PMN-PT heterostructures

We epitaxially grew the metamagnetic FeRh films on ferroelectric PMN-PT(001) substrates and investigated the electric control of magnetic properties. An MgO buffer layer is inserted to reduce the considerably large lattice mismatch of 5.44% between FeRh and PMN-PT, leading to a nice epitaxial growth with a relationship of FeRh[110](001)||MgO[100](001)||PMN-PT[100](001). The as-grown FeRh film shows a typical anti-ferromagnetic-to-ferromagnetic phase transition by means of varying the temperature. Because a growthinduced uniaxial magnetic anisotropy is superimposed on the in-plane four-fold magnetocrystalline anisotropy, the epitaxial FeRh film displays different kinds of multi-step hysteresis loops at various field orientations. An electric field applied on the PMN-PT substrate can remarkably increase the coercivity of FeRh film, which presents a butterfly type shape, indicating a strain-mediated magnetoelectric coupling. Because of the inhibitory effect of the remnant compressive strain on the phase transition, the critical transition temperature and the magnetization are obviously enhanced and reduced, respectively, after removing the electric effect. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study focused on epitaxial growth of FeRh films on PMN-PT substrates with the use of an MgO buffer layer to reduce lattice mismatch. Electric field applied on PMN-PT substrate significantly increased coercivity of FeRh film, displaying a butterfly type shape. FeRh film exhibited different types of multi-step hysteresis loops, and the critical transition temperature and magnetization were significantly affected by the inhibitory effect of remnant compressive strain after removing the electric effect.