Perpendicular Magnetic Tunnel Junctions With Low Resistance-Area Product: High Output Voltage and Bias Dependence of Magnetoresistance

We investigate the tunnel magnetoresistance (TMR) effect and its applied bias voltage dependence for perpendicular magnetic tunnel junctions (p-MTJs) with low resistance-area (RA) products of about 10 Ω · μm
²
. We obtain a maximum TMR ratio of 248% among the examined devices. The bias-voltage dependence of the TMR ratio for these junctions is almost the same as that for junctions with RA products of about 10-1000 Ω · μm
²
in the positive voltage region, while a fast drop in the TMR ratio is observed in the negative bias region. An output voltage of more than 200 mV is obtained for these p-MTJs.