title: 2D transition-metal diselenides: phase segregation, electronic structure, and magnetism.
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.
authors.affiliation: Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Manchanda
authors.forename: Ralph
authors.initials: R
authors.lastname: Skomski