Origin of ferromagnetism and the effect of doping on Fe3GeTe2. Issue 25 (18th June 2020)

• Record Type: Journal Article
• Authors: Jang, Seung Woo; Yoon, Hongkee; Jeong, Min Yong; Ryee, Siheon; Kim, Heung-Sik; Han, Myung Joon
• Is Part Of: Nanoscale. Volume 12:Issue 25(2020)
• Page Start: 13501
• Page End: 13506
• Publication Date: 2020-06-18
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr10171c
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Fe3 GeTe2 is found to have antiferromagnetic ground state spin order in its stoichiometric phase. It is a defect and doping that make this material ferromagnetic. Abstract : Recent experimental findings of two dimensional ferromagnetism in Fe3 GeTe2, whose critical temperature can reach room temperature by gating, has attracted great research interest. Here we performed elaborate ab initio studies using density functional theory, dynamical mean-field theory and magnetic force response theory. In contrast to the conventional wisdom, it is unambiguously shown that Fe3 GeTe2 is not ferromagnetic but is antiferromagnetic, carrying zero net moment in its stoichiometric phase. Fe defect and hole doping are the keys to make this material ferromagnetic as supported by previously disregarded experiments. Furthermore, we found that electron doping also induces the antiferro- to ferro-magnetic transition. It is crucial to understand the notable recent experiments on gate-controlled ferromagnetism. Our results not only reveal the origin of ferromagnetism of this material but also show how it can be manipulated with defects and doping.