High field tunneling magnetoresistance effects in FeCoGd(t)/AlO/FeCo multilayers

Tunneling magnetoresistance (TMR) effect has been extensively studied either in MTJs [1] or in insulating granular films, but few studies have been reported on the composite structure combined them together. In this presented work, the MTJs of FeCoGd(t)/AlO/FeCo have been fabricated. Different from conventional MTJ, the FeCoGd electrode was partially oxidized. A thin granular film due to the oxidation is likely to be found at the interface between the FeCoGd electrode and the barrier. The TMR effects of the composite MTJs have been studied.