Large inverse tunneling magnetoresistance in Co2Cr0.6Fe0.4Al∕MgO∕Co80Fe20 magnetic tunnel junctions

Magnetic tunnel junctions with the layer sequence Co2Cr0.6Fe0.4Al∕MgO∕Co80Fe20 were fabricated by magnetron sputtering at room temperature (RT). The samples exhibit a large inverse tunneling magnetoresistance (TMR) effect of up to −66% at RT. The largest value of −84% at 20K reflects a rather weak influence of temperature. The dependence on the voltage drop shows an unusual behavior with two almost symmetric peaks at ±600mV with large inverse TMR ratios and small positive values around zero bias.