Ferromagnetism in Two-Dimensional Dysprosium-Platinum Surface Alloy.

In this study, we comprehensively analyze single and triple layers of a new two-dimensional surface alloy, namely DyPt. Both are ferromagnetic materials with an in-plane easy magnetization axis and low Curie temperature on the order of a few Kelvins. Magnetic and electronic properties confirm weak interlayer coupling and the dominance of interactions within alloy layers. Atomic-scale investigation proved nearly the same atomic structure of the termination layer and varying moiré patterns. The electronic structures of single and triple layer DyPt are similar, consisting of a mixture of Dy and Pt electronic states. The intensity of these electronic states varies within the moiré pattern, similar to the surface local work function, demonstrating modulated coupling between the surface alloy and the substrate. The presented results provide essential knowledge for further research of this system in terms of its application in the growth of densely packed arrays of magnetic clusters and molecules.