Tunneling magnetoresistance and induced domain structure in Al2O3-based junctions

Magnetization reversal in sputtered Co and oxidized Co (CoOx) layers an studied using transport measurements and magneto-optic Kerr effect. When associated in a magnetic tunnel junction, the two magnetic layers show a strong ferromagnetic coupling. Using the tunnel magnetoresistive effect as a probe for micromagnetic studies, we show the existence of an unexpected domain structure in the soft Co layer. This domain structure originates from the duplication of the domain structure of the hard CoOx magnetic layer template into the soft Co layer via the ferromagnetic coupling.