Tunneling magneto thermocurrent in CoFeB/MgO/CoFeB based magnetic tunnel junctions

摘要

We study the tunneling magneto thermopower and tunneling magnetothermocurrent of CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJ). The devicesshow a clear change of the thermoelectric properties upon reversal of themagnetisation of the CoFeB layers from parallel to the antiparallelorientation. When switching from parallel to antiparallel the thermopowerincreases by up to 55% where as the thermocurrent drops by 45%. Theseobservations can be well explained by the Onsager relations taking into accountthe tunneling magneto resistance of the MTJ. These findings contrast previousstudies on AlO based MTJ systems, revealing tunneling magneto thermo power butno tunneling magneto thermocurrent.