Spin-reorientation transition in an Fe double-layer on W(110) induced by Dzyaloshinsky-Moriya interaction

Controlling the preferred direction of the magnetic moments is essential for the design of spintronic devices based on ultrathin films and
heterostructures. As the film thickness or the temperature is increased, the easy anisotropy axis is typically reoriented from an out-of-plane
direction preferred by surface and interface energy contributions to an in-plane alignment favored by the volume anisotropy terms. In this talk
present a study of the temperature-driven spin reorientation transition in two atomic layers of Fe on W(110) using well-tempered metadynamics simulations based on a spin model parametrized by ab initio calculations. It is found that the transition only takes place if
Dzyaloshinsky--Moriya interaction (DMI) is present in the system. This demonstrates that the chiral DMI does not only differentiate between
non-collinear spin structures with different rotational senses, but at finite temperatures it can also influence the orientation of the ferromagnetic state of ultrathin films. [1]
[1] B. Nagyfalusi, L. Udvardi, L. Szunyogh, and L. Rózsa, Physical Review B 102 134413 (2020)