Ab initio density functional study of phase stability and noncollinear magnetism in Mn

Summary, in English

The crystalline and magnetic structures of all known polymorphs of Mn have been investigated using generalized spin-density functional theory based on an unconstrained vector-field description of the magnetization density. We find that at atomic volumes smaller than 12 Å3, the magnetic ground state of α-Mn is collinear with magnetic moments ranging between 0 and 3 µB depending on the local symmetry of the atomic positions. At larger atomic volumes, a metastable collinear configuration coexists with a stable noncollinear state. The noncollinearity of the magnetic structure is driven by the appearance of magnetic moments on sites IV, leading to a frustration of exchange interactions in local triangular configurations. A similar situation is found in β-Mn, with a collinear structure with coexisting magnetic and nonmagnetic sites. The α-phase is found to be stable over a wide range of volumes; under compression a phase transition to hexagonal -Mn is predicted.

• Author: David Hobbs; Jürgen Hafner
• Publishing year: 2001
• Language: English
• Pages: 681-688
• Publication/Series: Journal of Physics: Condensed Matter
• Volume: 13
• Document type: Journal article
• Publisher: IOP Publishing
• Status: Published
• ISBN/ISSN/Other: ISSN: 1361-648X