Electronic origins of the giant volume collapse in the pyrite mineral
- Univ. of Nevada, Las Vegas, NV (United States)
- European Synchrotron Radiation Facility (ESRF), Grenoble (France)
- Univ. of Bayreuth (Germany)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Edinburgh, Scotland (United Kingdom)
- European Synchrotron Radiation Facility (ESRF), Grenoble (France); Technical Univ. of Denmark, Lyngby (Denmark)
- European Synchrotron Radiation Facility (ESRF), Grenoble (France); Phillip Morris International, Neuchâtel (Switzerland)
- Inst. Laue-Langevin (ILL), Grenoble (France)
- Ehime Univ., Matsuyama (Japan)
- Univ. of Bourgogne (France)
The pyrite mineral MnS2 was recently shown to undergo a giant pressure-induced volume collapse at 12 GPa, via a disordered intermediate phase. The high pressure arsenopyrite phase is stabilised by metal-metal bonding, a mechanism now shown to be ubiquitous for Mn2+ chalcogenides. Here we report a spectroscopic investigation of this transition up to pressures of 22 GPa. Using XANES we show that the transition does not involve a change in oxidation state, consistent with the arsenopyrite crystal structure proposed at high pressure. Notably, the XANES spectrum is almost identical in the pressure-induced disordered phase, and after crystallisation induced by laser-heating. The former is therefore a `valence bond glass', and is likely disordered due to kinetic hindrance of the phase transition. We also detect electronic changes in the compressed pyrite phase, and this is con rmed by Raman scattering which shows that the disulphide vibrations in the pyrite phase saturate before the volume collapse. Together with detailed DFT calculations, these results indicate that electronic changes precede valence bond formation between the Mn2+ cations.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1481068
- Alternate ID(s):
- OSTI ID: 1636698
- Report Number(s):
- LLNL--JRNL-758730; {"Journal ID: ISSN 0022-4596",939374}
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: C Vol. 269; ISSN 0022-4596
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Probing disorder in high-pressure cubic tin (IV) oxide: a combined X-ray diffraction and absorption study
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journal | May 2019 |
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