Ballistic current transport studies of ferromagnetic multilayer films and tunnel junctions (invited)

Abstract

Three applications of ballisticelectron microscopy are used to study, with nanometer-scale resolution, the magnetic and electronic properties of magnetic multilayerthin films and tunnel junctions. First, the capabilities of ballistic electron magnetic microscopy are demonstrated through an investigation of the switching behavior of continuous Ni 80 Fe 20 /Cu/Co trilayerfilms in the presence of an applied magnetic field. Next, the ballistic, hot-electron transport properties of Co films and multilayers formed by thermal evaporation and magnetron sputtering are compared, a comparison which reveals significant differences in the ballistic transmissivity of thin filmmultilayers formed by the two techniques. Finally, the electronic properties of thin aluminum oxide tunnel junctions formed by thermal evaporation and sputter deposition are investigated. Here the ballisticelectron microscopy studies yield a direct measurement of the barrier height of the aluminum oxide barriers, a result that is invariant over a wide range of oxidation conditions.