Micromagnetics of Magnetization Reversal in Patterned Magnetic Recording Medium

Abstract

Micromagnetic modeling based on LLG formalism was used to study the magnetization reversal processes in patterned recording layer. The write fields generated by an idealized single pole write head with a uniformly magnetized air-bearing surface (ABS) were used. The applied write field is highly nonuniform within a bit, making consistent comparison based on its values difficult. The effects of the bit geometry, medium thickness, head/medium magnetic spacing (flying height), ABS geometry, the effects of neighboring bits on magnetization reversal, and the sensitivity of the write process to non-zero write misregistration (WMR) were investigated. It was shown that the larger ABS cross-section heads generate stronger write fields resulting in a capability of using higher anisotropy/better thermal stability media materials. Also, the sensitivity on WMR is weaker for larger ABS cross-section heads simplifying the optimization of a recording system design.