Atomic level micromagnetic model of recording media switching at elevated temperatures

TL;DR

This paper introduces an atomic-level micromagnetic model for granular recording media to analyze grain switching at high temperatures, revealing nuanced differences from traditional uniform models.

Contribution

The study develops an atomic-level model capturing non-uniform reversal modes and compares it with traditional uniform grain models for high-anisotropy media.

Findings

Atomic-level reversal reduces switching field slightly.

Larger fluctuations observed in atomic-level model.

Results relevant for energy-assisted magnetic recording.

Abstract

An atomic level micromagnetic model of granular recording media is developed and applied to examine external field-induced grain switching at elevated temperatures which captures non-uniform reversal modes. The results are compared with traditional methods which employ the Landau-Lifshitz-Gilbert equations based on uniformly magnetized grains with assigned intrinsic temperature profiles for $M(T)$ and $K(T)$. Using nominal parameters corresponding to high-anisotropy FePt-type media envisioned for Energy Assisted Magnetic Recording, our results demonstrate that atomic-level reversal slightly reduces the field required to switch grains at elevated temperatures, but results in larger fluctuations, when compared to a uniformly magnetized grain model.