We investigate the switching field distribution and the resulting bit errorrate of exchange coupled ferri-/ferromagnetic bilayer island arrays bymicromagnetic simulations. Using islands with varying microstructure andanisotropic properties, the intrinsic switching field distribution is computed.The dipolar contribution to the switching field distribution is obtainedseparately by using a model of a triangular patterned island array resembling$1.4\,\mathrm{Tb/in}^2$ bit patterned media. Both contributions are computedfor different thickness of the soft exchange coupled ferrimagnet and also forferromagnetic single phase FePt islands. A bit patterned media with a bilayerstructure of FeGd($5\,\mathrm{nm}$)/FePt($5\,\mathrm{nm}$) shows a bit errorrate of $10^{-4}$ with a write field of $1.16\,\mathrm{T}$.
展开▼
