PROJECT TITLE :

Perpendicular Exchange Bias of [Pt/Co]5/IrMn Multilayers on Self-Organized Hexagonally Patterned Nanodots

ABSTRACT:

[Pt/Co]5/IrMn multilayers were deposited on hexagonally patterned nanodots on the backside of anodized alumina oxide (AAO) templates and thermally oxidized Si substrates. AAO templates with different diameters of about fifty, 60, 130 and four hundred nm nanodots were used to fabricate the exchange-biased nanostructures and investigate the scale effect on the perpendicular exchange bias. With decreasing nanodots diameter, the multilayers exhibited massive variations in both exchange bias field HE and coercivity HC. Compared to the flat film, HE of the nanodots samples was considerably enhanced, that will be attributed to the reduction in antiferromagnetic and ferromagnetic domain sizes induced by the curved morphology and domain wall pinning between 2 adjacent magnetic nanocaps. Unexpectedly, the fifty nm nanodot sample had higher thermal stability than the flat film sample.