Voltage-controlled magnetic anisotropy and voltage-induced Dzyaloshinskii-Moriya interaction change at the epitaxial Fe(001)/MgO(001) interface engineered by Co and Pd atomic-layer insertion

Abstract

We fabricated epitaxial multilayers with Co and Pd atomic-layer insertion at Fe(001)/MgO(001) interface and systematically investigated voltage-controlled magnetic anisotropy (VCMA) and voltage-induced interfacial Dzyaloshinskii-Moriya interaction $(i\mathrm{DMI})$ change. The VCMA and $i\mathrm{DMI}$ change was characterized by spin-wave spectroscopy. We found that the VCMA was increased by Co and Pd insertions to \ensuremath{-}180 fJ/Vm in the Fe/Co/Pd/MgO system. We also found a large voltage-induced $i\mathrm{DMI}$ change of 65 fJ/Vm. The postannealing dependence of the VCMA and $i\mathrm{DMI}$ change was also characterized to investigate the influence of the change in chemical ordering around the MgO interface.