Fabrication of fully epitaxial Co2MnSi∕MgO∕Co2MnSi magnetic tunnel junctions

Abstract

Fully epitaxial magnetic tunnel junctions (MTJs) were fabricated with full-Heusler alloy Co2MnSi thin films as both lower and upper electrodes and with a MgO tunnel barrier. The fabricated MTJs showed clear exchange-biased tunnel magnetoresistance (TMR) characteristics with high TMR ratios of 179% at room temperature (RT) and 683% at 4.2K. In addition, the TMR ratio exhibited oscillations as a function of the MgO tunnel barrier thickness (tMgO) at RT, having a period of 0.28nm, for tMgO ranging from 1.8to3.0nm.