Spin-driven symmetry breaking in the frustrated fcc pyrite MnS2. (19th May 2015)

• Record Type: Journal Article
• Authors: Kimber, Simon A J; Chatterji, Tapan
• Is Part Of: Journal of physics. Volume 27:Number 22(2015)
• Publication Date: 2015-05-19
• Subjects: frustrated magnetism -- symmetry breaking -- materials; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/22/226003
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We report the characterisation of natural samples of the cubic pyrite mineral MnS2 using very high resolution synchrotron x-ray diffraction techniques. At low temperatures we find a new low temperature polymorph, which results from coupling between magnetic and lattice degrees of freedom. Below the magnetic ordering temperature T N = 48 K, we detect a pseudo-tetragonal distortion with a tiny c / a ratio of 1.0006. The structure can be refined in the space group Pbca The symmetry lowering reduces magnetic frustration in the fcc Mn 2+ lattice and is likely responsible for the previously reported lock-in of the magnetic propagation vector. This behaviour is similar to the spin-Peierls phase transitions reported in other three-dimensional Heisenberg magnets like the chromate spinels.