Back to Search
Start Over
Giant pressure-induced volume collapse in the pyrite mineral MnS2
- Source :
- Proc. Nat. Acad. Sci. 111 5106-5110 (2014)
- Publication Year :
- 2013
-
Abstract
- Dramatic volume collapses under pressure are fundamental to geochemistry and of increasing importance to fields as diverse as hydrogen storage and high-temperature superconductivity. In transition metal materials, collapses are usually driven by so-called spin-state transitions, the interplay between the single-ion crystal field and the size of the magnetic moment. Here we show that the classical S=5/2 mineral Hauerite undergoes an unprecedented 22 % collapse driven by a conceptually different magnetic mechanism. Using synchrotron x-ray diffraction we show that cold compression induces the formation of a disordered intermediate. However, using an evolutionary algorithm we predict a new structure with edge-sharing chains. This is confirmed as the thermodynamic groundstate using in situ laser heating. We show that magnetism is globally absent in the new phase, as low-spin quantum S=1/2 moments are quenched by dimerisation. Our results show how the emergence of metal-metal bonding can stabilise giant spin-lattice coupling in Earth's minerals.<br />Comment: Published version, minor changes
- Subjects :
- Condensed Matter - Strongly Correlated Electrons
Subjects
Details
- Database :
- arXiv
- Journal :
- Proc. Nat. Acad. Sci. 111 5106-5110 (2014)
- Publication Type :
- Report
- Accession number :
- edsarx.1305.7119
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1073/pnas.1318543111