Origin of itinerant ferromagnetism in two-dimensional Fe<sub>3</sub>GeTe<sub>2</sub> *
Xi Chen, Zheng‐Zhe Lin, Li-Rong Cheng
Abstract
Magnetic order in two-dimensional systems was not supposed to exist at finite temperature. In recent years, the successful preparation of two-dimensional ferromagnetic materials such as CrI 3 , Cr 2 Ge 2 Te 6 , and Fe 3 GeTe 2 opens up a new chapter in the remarkable field of two-dimensional materials. Here, we report on a theoretical analysis of the stability of ferromagnetism in Fe 3 GeTe 2 . We uncover the mechanism of holding long-range magnetic order and propose a model to estimate the Curie temperature of Fe 3 GeTe 2 . Our results reveal the essential role of magnetic anisotropy in maintaining the magnetic order of two-dimensional systems. The theoretical method used here can be generalized to future research of other magnetic two-dimensional systems.