Characterization of magnetic tunnel junctions using IETS

In this paper inelastic electron tunneling spectroscopy measurements are presented on tunnel junctions containing both magnetic and nonmagnetic electrodes. Magnon excitations have been found near zero voltage; phonons are observed between 30 and 110 mV. Therefore, a model description of the transport properties of magnetic tunnel junctions at elevated temperatures or non-zero bias voltage should include both inelastic contributions.