TEMPERATURE-DEPENDENCE OF THE SPIN TUNNELING MAGNETORESISTIVE EFFECT ON NIFE CO/AL2O3/CO/NIFE/FEMN JUNCTIONS/

Spin-valve type spin tunneling junctions using contact metal masks hav e been fabricated. The annealing effect and temperature dependence of the tunneling magnetoresistance (TMR) ratio and saturated resistance ( R-s) have been investigated, As-prepared NiFe/Co/Al2O3/Co/NiFe/FeMn ju nctions show a spin-valve like MR curve and a TMR ratio of up to 28% a t room temperature. The temperature dependence of the TMR ratio and R- s is affected by the annealing. For annealed junction, the TMR ratio s lightly decreases with increasing temperature and rapidly decreases ar ound 418 K because of the disappearance of an exchange bias of the FeM n layer.