Enhanced spin injection and voltage bias in (Zn,Co)O/MgO/(Zn,Co)O magnetic tunnel junctions

Abstract

The tunnel magnetoresistance (TMR) and voltage bias dependence of (Zn,Co)O/MgO/(Zn,Co)O magnetic tunnel junctions (MTJs) are investigated in this study. Using MgO as the tunnel barrier, a positive TMR of 46.8% is obtained at 2 T at 4 K with the applied current of 1 μA. The MTJs are found to show a high voltage bias with an ultrahigh V1/2, for which half of the TMR remains, exceeding 10 V compared with other conventional MTJs. These results are promising for further research on MgO as a tunnel barrier in the application of diluted magnetic semiconductor-based spintronic devices.