Tunable defect-induced magnetism in Pt-based dichalcogenides

The much-sought-after magnetism in two-dimensional (2D) materials is not only important for its potential applications in spintronic and magneto-optical devices, but also due to its impact on our understanding of fundamental principles in solid state physics. In addition, 2D magnetic solids offer a unique opportunity for heterogeneous assembly with potentially new emergent phenomena. Amongst recent reports of magnetic 2D materials, magnetism was experimentally observed in PtSe₂ thin films and was attributed to the naturally-occuring Pt vacancies. In this theoretical work, we show that the defect-induced magnetism in the PtSe₂ thin films is highly sensitive to: (i) the PtSe₂ layer-thickness (ii) defect density, (iii) the strain in the layer, and (iv) substrate choice. These different factors dramatically modify magnetic properties such as, the magnitude of the local moments, strength of coupling, and even the nature of coupling between the moments. The tunability of the magnetic properties in the Pt-based dichalcogenides can be used to design novel devices for magnetoelectric and magneto-optics applications.