Uniaxial magnetic anisotropy of Ni–Fe films exchange-coupled with Fe dot-arrays

Abstract We have investigated uniaxial magnetic anisotropy of systems of [(Fe rectangular dot-arrays)/(Ni-20 at% Fe continuous films)]. The Fe dot-arrays show uniaxial anisotropy because of their own rectangular shape, when the aspect ratio of the Fe dots is high. The whole systems of [(Fe dot-arrays)/(Ni–Fe films)] also show uniaxial anisotropy in the case of high aspect ratios because the Fe dot-arrays directly contact with the Ni–Fe continuous films. The uniaxial anisotropy of the whole systems of [(Fe dot-arrays)/(Ni–Fe films)] increases as the width of the Fe dots decreases, when the length of the Fe dots is constant.