Inelastic electron tunneling spectroscopy and bias voltage dependence of magnetic tunnel junctions with polycrystalline Co2MnSi electrode

Abstract

Spintronics needs half-metallic materials implemented in technologically relevant devices. We prepare Co2MnSi/AlOx/Co7Fe3 junctions showing a tunneling magnetoresistance of 94.6% at 1 mV and 20 K. Their inelastic electron tunneling spectra at 20 K show typical magnon and phonon excitations in the electrode and the barrier and an additional shoulder around −22 mV not observed in Co7Fe3/AlOx/Ni81Fe19 reference junctions. Furthermore, the bias voltage and temperature dependence of the tunneling magnetoresistance is considerably larger than for the reference junctions. The transport properties are discussed with respect to a variety of current contributions associated with the structural and magnetic properties of the Co2MnSi/AlOx interface.