Abstract
A micromagnetic model of an exchange bias bilayer is used to examine the impact of the physical structure and the easy axis dispersion of the antiferromagnetic (AF) layer on the exchange bias field (HEB) in an IrMn/CoFe system. Because of the different timescales, the magnetization dynamics of the IrMn and CoFe layers are modelled using respectively a kinetic Monte Carlo (kMC) approach and Landau-Lifshitz-Gilbert (LLG) equation. The easy axis dispersion is modelled using a Gaussian distribution. The calculations show that HEBincreases with increasing IrMn thickness and grain size, in agreement with experimental work. Moreover, the model allows the visualization of the switching process at the micromagnetic level to reveal the reversal mechanism. We find that the effect of AF easy axis distribution not only strongly affects the reduction of HEBbut also drives non-coherent behaviour in the reversal mechanism. This confirms that the easy axis distribution is an important factor with strong impact on the magnetic properties and exchange bias field of an exchange bias system.
Original language | English |
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Article number | 045002 |
Number of pages | 8 |
Journal | Journal of Physics D: Applied Physics |
Volume | 53 |
Issue number | 4 |
Early online date | 18 Nov 2019 |
DOIs | |
Publication status | Published - Jan 2020 |
Bibliographical note
This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.Keywords
- Easy axis distribution
- Exchange bias field
- Kinetic monte carlo
- Landau-lifshitz-gilbert equation