Micromagnetic simulation study on exchange-coupled composite media

Abstract

The magnetic dynamics of the total recording system with a single pole head, recording layer (RL), and semihard layer (SHL) or soft underlayer were examined by a three-dimensional micromagnetic model to understand the recording characteristics of the composite perpendicular media. The effects of the exchange strength and the SHL properties on read/write properties and the possibility of the composite media for high recording density were investigated. By comparing the three different cases: (i) single layer, (ii) conventional double-layered perpendicular media, and (iii) exchange-coupled composite media, the improvement of writability and signal-to-noise ratio (SNR) was studied. The effect of interlayer exchange coupling (J(ex)) between the RL and the SHL on SNR in the exchange-coupled composite media will be discussed. The effect of nonmagnetic grain-boundary region in the RL and the SHL on read/write properties will be also discussed. (C) 2006 American Institute of Physics.