High magnetoresistance in Co–Fe–B-based double barrier magnetic tunnel junction

The magnetic transport properties of the double barrier magnetic tunnel junctions (DBMTJs) with amorphous Co–Fe–B electrodes, deposited by magnetron sputtering and patterned using optical lithography combined with lift-off technique, were investigated. A high tunnel magnetoresistance (TMR) ratio of 90.3% and 59.4%, resistance-area product of about 6.2 and 5.5 kΩ μm2 at 4.2 K and room temperature, respectively, and a high bias voltage at which the TMR signal decreased to half of its maximum value, V1/2 =1.14 V at negative bias voltage were measured experimentally for the DBMTJs. These results show that the DBMTJs are promising candidates for spin electronic devices.