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Title: Shear-Induced Isostructural Phase Transition and Metallization of Layered Tungsten Disulfide under Nonhydrostatic Compression

Pressure-induced structural and electronic transformations of tungsten disulfide (WS 2) have been studied to 60 GPa, in both hydrostatic and non-hydrostatic conditions, using four-probe electrical resistance measurements, micro-Raman spectroscopy and synchrotron x-ray diffraction. Our results show the evidence for an isostructural phase transition from hexagonal 2H c phase to hexagonal 2H a phase, which accompanies the metallization at ~37 GPa. This isostructural transition occurs displacively over a large pressure range between 15 and 45 GPa and is driven by the presence of strong shear stress developed in the layer structure of WS 2 under non-hydrostatic compression. Interestingly, this transition is absent in hydrostatic conditions using He pressure medium, underscoring its strong dependence on the state of stress. We also attribute the absence to the incorporation of He atoms between the layers, mitigating the development of shear stress. We also conjecture a possibility of magnetic ordering in WS 2 that may occur at low temperature near the metallization.
Authors:
 [1] ;  [1]
  1. Washington State Univ., Pullman, WA (United States). Dept. of Chemistry and Inst. of Schock Physics
Publication Date:
Grant/Contract Number:
NA0002006; NA0001974; FG02-99ER45775; 1203834; HDTRA1-12-01-0020
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 120; Journal Issue: 9; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Carnegie Inst. of Washington, Pullman, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1379180

Duwal, Sakun, and Yoo, Choong-Shik. Shear-Induced Isostructural Phase Transition and Metallization of Layered Tungsten Disulfide under Nonhydrostatic Compression. United States: N. p., Web. doi:10.1021/acs.jpcc.5b10759.
Duwal, Sakun, & Yoo, Choong-Shik. Shear-Induced Isostructural Phase Transition and Metallization of Layered Tungsten Disulfide under Nonhydrostatic Compression. United States. doi:10.1021/acs.jpcc.5b10759.
Duwal, Sakun, and Yoo, Choong-Shik. 2016. "Shear-Induced Isostructural Phase Transition and Metallization of Layered Tungsten Disulfide under Nonhydrostatic Compression". United States. doi:10.1021/acs.jpcc.5b10759. https://www.osti.gov/servlets/purl/1379180.
@article{osti_1379180,
title = {Shear-Induced Isostructural Phase Transition and Metallization of Layered Tungsten Disulfide under Nonhydrostatic Compression},
author = {Duwal, Sakun and Yoo, Choong-Shik},
abstractNote = {Pressure-induced structural and electronic transformations of tungsten disulfide (WS2) have been studied to 60 GPa, in both hydrostatic and non-hydrostatic conditions, using four-probe electrical resistance measurements, micro-Raman spectroscopy and synchrotron x-ray diffraction. Our results show the evidence for an isostructural phase transition from hexagonal 2Hc phase to hexagonal 2Ha phase, which accompanies the metallization at ~37 GPa. This isostructural transition occurs displacively over a large pressure range between 15 and 45 GPa and is driven by the presence of strong shear stress developed in the layer structure of WS2 under non-hydrostatic compression. Interestingly, this transition is absent in hydrostatic conditions using He pressure medium, underscoring its strong dependence on the state of stress. We also attribute the absence to the incorporation of He atoms between the layers, mitigating the development of shear stress. We also conjecture a possibility of magnetic ordering in WS2 that may occur at low temperature near the metallization.},
doi = {10.1021/acs.jpcc.5b10759},
journal = {Journal of Physical Chemistry. C},
number = 9,
volume = 120,
place = {United States},
year = {2016},
month = {2}
}