Effect of the anisotropy distribution on the coercive field and switching field distribution of bit patterned media

We present a systematic study on the magnetization reversal in square arrays of magnetic nanostructures. To account for the unavoidable inhomogeneities of the magnetic properties due to, i.e., template preparation, a distribution of magnetic anisotropy values was taken into account. We show that the variation in magnetic anisotropy within an array of magnetic nanostructures and the influence of magnetic dipole-dipole interaction between the individual bits with separation distance is crucial for the performance of bit patterned media (BPM) concerning in particular the switching field distribution (SFD). Interestingly, a narrowing of the SFD was found with the angle between the direction of the external magnetic field and easy axis of magnetization, which is an important aspect for the usability of BPM with tilted anisotropy at ultrahigh storage densities beyond 1 Tbit/in.².