Giant tunneling magnetoresistance in Co2MnSi/Al-O /Co 2MnSi magnetic tunnel junctions

Abstract

Magnetic tunnel junctions (MTJs) with a stacking structure of Co2 MnSiAl-O Co2 MnSi were fabricated using magnetron sputtering system. Fabricated MTJ exhibited an extremely large tunneling magnetoresistance (TMR) ratio of 570% at low temperature, which is the highest TMR ratio reported to date for an amorphous Al-O tunneling barrier. The observed dependence of tunneling conductance on bias voltage clearly reveals the half-metallic energy gap of Co2 MnSi. The origins of large temperature dependence of TMR ratio were discussed on the basis of the present results. © 2006 American Institute of Physics.