Micromagnetic simulations of sweep-rate dependent coercivity in perpendicular recording media

TL;DR

This study uses micromagnetic simulations to analyze how thermal fluctuations influence the sweep-rate dependent coercivity in perpendicular magnetic recording media, comparing single-layer and exchange-coupled-composite media at various temperatures and angles.

Contribution

It demonstrates that ECC media exhibit weaker sweep-rate dependence, indicating greater thermal stability, and evaluates the applicability of Sharrock-like scaling to different media types.

Findings

ECC media show less sweep-rate dependence, indicating higher thermal stability.

Sharrock-like scaling fits single-layer media with normal field, but not others.

Thermal fluctuations significantly affect coercivity in magnetic recording media.

Abstract

The results of micromagnetic simulations are presented which examine the impact of thermal fluctuations on sweep rate dependent coercivities of both single-layer and exchange-coupled-composite (ECC) perpendicular magnetic recording media. M-H loops are calculated at four temperatures and sweep rates spanning five decades with fields applied normal to the plane and at 45 degrees. The impact of interactions between grains is evaluated. The results indicate a significantly weaker sweep-rate dependence for ECC media suggesting more robustness to long-term thermal effects. Fitting the modeled results to Sharrock-like scaling proposed by Feng and Visscher [J. Appl. Phys. 95, 7043 (2004)] is successful only in the case of single-layer media with the field normal to the plane.