Recent Research Projects

The exchange bias setting process in magnetic read sensors

In collaboration with:

The aim of this research project was to develop a model which would describe the setting process of exchange biased layers in magnetic read sensors. This is of importance in the hard drive industry as larger exchange bias produces a better signal from the read sensor.

To create a model that could describe the long timescale involed in the annealing process a kinetic Monte-Carlo algorithm was used to solve the pinning antiferromagnetic (AFM) layer. The rest of the read stack was described with micromagnetic formalism using the LLG equation.

Publications

Using exchange bias to stabilise superparamagnetic grains for recording applications

In this work we have investigated the stabilising effects of the anti-ferromagnet (AFM) in core-shell nanoparticles. Our results have demonstarted an increase in the energy barrier along the bias direction, with a corresponding decrease of the barrier in the opposite direction. In order to permit magnetic recording, which essentially requires a bi-stable system, we propose a heat-assisted recording method, whereby both the ferromagnet (FM) and antiferromagnet (AF) are switched. Upon heating to the Néel temperature of the AFM, the magnetic order is destroyed allowing switching of the FM core with a small applied field. Thermal stability of the core is then restored after cooling back to room temperature.

Publications