Magnetization reversal of nanostructured tunnel junctions from prepatterned substrates
Résumé
Nanostructured tunnel junctions with composition Al2O3/Ta/Ru/Mn51.5Pt48.5/Co90Fe10/Al oxidized/Co90Fe10/Ni81Fe19/Ta were prepared on prepatterned silicon substrates, consisting of rectangular dots with dimensions as small as 100×400 nm2 and different spacings. Reduced lateral dimensions lead to an enhancement of the exchange bias field by comparison to continuous films. Magnetic force microscopy images taken at remanence indicate a mixture of magnetic states corresponding to the different relative orientations of the magnetizations of the pinned and the free layers. Significant dipolar interactions between the dots also proved to contribute to the complexity of the magnetization reversal of the stacks.