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 $\Omega\cdot \mu$ m $^{2}$ . 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 $\Omega \cdot\mu$ m $^{2}$ 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.