Pinning of magnetic domain walls to structural defects in thin layers within a Heisenberg-type model

The interaction between domain walls and structural defects in equiatomic L1₀ FePt, antiphase boundaries and microtwins, was investigated by numerical simulations at atomic scale based on a Heisenberg model. It was shown that domain walls are strongly pinned, with depinning fields reaching a few teslas for the thickest microtwins. The potential well of the domain wall pinned in the microtwin is found to be asymmetric as a result of the pinning process. This results in depinning fields depending on the direction of propagation of the wall.