Micromagnetics of percolated perpendicular medium for 1 Tb/in2 and beyond

A fully exchange coupled perpendicular medium with densely distributed nonmagnetic pinning sites has been proposed. In the novel microstructure configuration, the dense domain wall pinning sites enable the perpendicular medium to obtain narrow transitions and small transition noise. Using the micromagnetic modeling, the macromagnetic properties and recording performances of the novel medium have been investigated. The results show that the medium transition noise can be optimized with a moderate exchange coupling constant. The dynamic recording processes are studied with different damping constants and recording field amplitudes. Our study indicates that the switching time of the percolated medium is smaller than I ns even with low switching field and small damping constant.