Areal density limits for perpendicular magnetic recording

A strategy for high-density perpendicular magnetic recording with a soft underlayer is introduced. The approach is based on three concepts: 1) the nonzero magnetic susceptibility of the recording layer; 2) the use of intergranular exchange to partially cancel magnetostatic effects; and 3) a novel head architecture. Micromagnetic simulations involving recording head, soft underlayer, and recording layer are employed to specify a particularly advantageous design. It is shown that the expected density approaches 1 Tbit/[in.sup.2]. Index Terms--High-density perpendicular recording, intergranular exchange, micromagnetics, permeability.