Interfacial capacitance effects in magnetic tunneling junctions

Abstract We have investigated the AC transport properties of magnetic tunnel junctions (MTJ) in order to characterize interfacial properties. One such property is interfacial charge accumulation, which leads to a voltage drop in the electrodes of the MTJ and the measured capacitance differing from the geometrical capacitance. Through measurement of capacitance spectra, we have extracted an interfacial capacitance of 16 μF/cm 2 per interface and a screening length of 0.55 A for FeNi electrodes.