Perpendicular exchange bias of [Pt/Co](n)/CoO multilayer on ordered nanosphere arrays

TitlePerpendicular exchange bias of [Pt/Co](n)/CoO multilayer on ordered nanosphere arrays
Publication TypeJournal Article
Year of Publication2012
AuthorsZhang, YJ, Li, W, Li, J, Zhang, YM, Wang, YX, Yang, SY, Liu, SS, Wu, LC, Beach, GSD, Yang, JH
JournalJournal of Applied Physics
Volume111
Issue5
Pagination053925
Date Published2012/03/01/
Abstract

Polystyrene nanosphere arrays are used as the substrate for [Pt/Co](n)CoO multilayer deposition. The effects of nanosphere size and CoO thicknesses on the magnetic properties of [Pt/Co](n)CoO multilayer nanocaps are investigated. With decreasing nanosphere diameter, the nanocaps exhibit systematic variations of coercivity, exchange bias field, and switching field distribution. The switching field distribution is broadened and the coercivity is enhanced when the nanosphere sizes decrease, which are ascribed to the magnetic dipole-dipole interaction of the isolated nanocaps when the thickness of multilayer is far below the nanosphere radius. The mixture formation and the anisotropy direction changes of Co and CoO interface play an important role in the variation of the exchange bias field when the multilayer film is deposited on the nanosphere with diameter of 60 nm. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3693044]