2D transition-metal diselenides: phase segregation, electronic structure, and magnetism. (21st January 2016)

• Record Type: Journal Article
• Authors: Manchanda, Priyanka; Skomski, Ralph
• Is Part Of: Journal of physics. Volume 28:Number 6(2016)
• Publication Date: 2016-01-21
• Subjects: DFT -- phase segregation -- magnetism; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/28/6/064002
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Density-functional theory is used to investigate the phase-segregation behavior of two-dimensional transition-metal dichalcogenides, which are of current interest as beyond-graphene materials for optoelectronic and spintronic applications. Our focus is on the behavior of W1− x V x Se2 monolayers, whose end members are semiconducting WSe2 and ferromagnetic VSe2 . The energetics favors phase segregation, but the spinodal decomposition temperature is rather low, about 420 K. The addition of V leads to a transition from a nonmagnetic semiconductor to a metallic ferromagnet, with a ferromagnetic moment of about 1.0 μ B per V atom. The transition is caused by a p-type doping mechanism, which shifts the Fermi level into the valence band. The finite-temperature structure and magnetism of the diselenide systems are discussed in terms of Onsager-type critical fluctuations and Bruggeman effective-medium behavior.