Curie temperature modulated structure to improve the performance in heat-assisted magnetic recording

TL;DR

This paper explores how modulating the Curie temperature structure in heat-assisted magnetic recording improves performance by reducing noise and compensating for temperature gradient effects, using atomistic simulations.

Contribution

It introduces a method of using a graded Curie temperature to mitigate noise and performance loss in HAMR due to temperature gradients.

Findings

Temperature reduction influences switching probability and noise.

A graded Curie temperature can compensate for performance loss.

DC noise is reduced with a Curie temperature gradient.

Abstract

We investigate how a temperature reduction in z-direction influences the switching probability and the noise in heat-assisted magnetic recording (HAMR) for a bit in bit-patterned media with dimensions d=5nm and h=10nm. Pure hard magnetic bits are considered and simulations with a continuous laser pulse are performed using the atomistic simulation tool VAMPIRE. The results display that the switching behavior shows a thermally induced exchange spring effect. Simultaneously, both the AC and the DC noise increase. Additionally, we illustrate how an artificial Curie temperature gradient within the material can compensate the HAMR performance loss due to the temperature gradient. Further, due to the graded Curie temperature, DC noise can be reduced compared to a structure where no temperature gradient is considered.