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

Magnetic tunnel junctions (MTJs) with a stacking structure of Co2MnSi/Al-O/Co2MnSi 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 Co2MnSi. The origins of large temperature dependence of TMR ratio were discussed on the basis of the present results.(c) 2006 American Institute of Physics.