Strain-induced magnetic transition of HfSe₂ and PtSe₂ nanoribbons: A first-principles study

Hsin-Mei Ho^1*, Shih-Chuan Lien¹, Yu-Hui Tang¹

¹Department of Physics, National Central University, Taoyuan, Taiwan

* Presenter:Hsin-Mei Ho, email:sabrina0719@gmail.com

Edge state in materials has become a key aspect in solid-state physics. Recent research not only focuses on the fundamental properties of low-dimensional materials, such as the well-known graphene and the transition metal dichalcogenides (TMDs), the exploration of new properties based on these materials also arouses intensive studies. As the appearance of magnetic states in graphene nanoribbon is ascribed to the zigzag edge geometry, TMD nanoribbons with zigzag edges are found to have similar magnetic properties with a different extent of complexity and variability because of a wide range of electronic properties and structural symmetries. Since then, TMD nanoribbons could have much potential for application.
First-principles calculation is applied to investigate the structural, electronic, and magnetic properties of HfSe₂ and PtSe₂ nanoribbons. This work demonstrates the uniqueness of zigzag edge with intrinsic magnetic properties. The analysis of magnetic states begins with the structural optimization of nanoribbon after edges are created. The magnetizations of both HfSe₂ and PtSe₂ nanoribbons are connected to the broken octahedral symmetry at the zigzag edges. As an illustration of the relation between the edge structures and the magnetization, strain along different direction is applied to the nanoribbons. While the magnetization of HfSe₂ nanoribbon has a change in its magnitude under strain, there is a magnetic-nonmagnetic transition in PtSe₂ nanoribbon under compressive strain, which indicates that the magnetization is tunable and has possibilities in application.

Keywords: Transition metal dichalcogenides, nanoribbon, First-principles, strain effect, magnetism