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Title: Pressure-induced structural transformation of CaC{sub 2}

Abstract

The high pressure structural changes of calcium carbide CaC{sub 2} have been investigated with Raman spectroscopy and synchrotron X-ray diffraction (XRD) techniques in a diamond anvil cell at room temperature. At ambient conditions, two forms of CaC{sub 2} co-exist. Above 4.9 GPa, monoclinic CaC{sub 2}-II diminished indicating the structural phase transition from CaC{sub 2}-II to CaC{sub 2}-I. At about 7.0 GPa, both XRD patterns and Raman spectra confirmed that CaC{sub 2}-I transforms into a metallic Cmcm structure which contains polymeric carbon chains. Along with the phase transition, the isolated C{sub 2} dumbbells are polymerized into zigzag chains resulting in a large volume collapse with 22.4%. Above 30.0 GPa, the XRD patterns of CaC{sub 2} become featureless and remain featureless upon decompression, suggesting an irreversible amorphization of CaC{sub 2}.

Authors:
; ; ; ; ; ; ; ;  [1]
  1. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)
Publication Date:
OSTI Identifier:
22658018
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 144; Journal Issue: 19; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AMORPHOUS STATE; CALCIUM CARBIDES; EXPERIMENTAL DATA; MONOCLINIC LATTICES; ORTHORHOMBIC LATTICES; PHASE TRANSFORMATIONS; PRESSURE RANGE GIGA PA; PRESSURE RANGE MEGA PA 10-100; RAMAN SPECTRA; RAMAN SPECTROSCOPY; X-RAY DIFFRACTION

Citation Formats

Wang, Lu, Huang, Xiaoli, Li, Da, Huang, Yanping, Bao, Kuo, Li, Fangfei, Wu, Gang, Liu, Bingbing, and Cui, Tian, E-mail: cuitian@jlu.edu.cn. Pressure-induced structural transformation of CaC{sub 2}. United States: N. p., 2016. Web. doi:10.1063/1.4948705.
Wang, Lu, Huang, Xiaoli, Li, Da, Huang, Yanping, Bao, Kuo, Li, Fangfei, Wu, Gang, Liu, Bingbing, & Cui, Tian, E-mail: cuitian@jlu.edu.cn. Pressure-induced structural transformation of CaC{sub 2}. United States. doi:10.1063/1.4948705.
Wang, Lu, Huang, Xiaoli, Li, Da, Huang, Yanping, Bao, Kuo, Li, Fangfei, Wu, Gang, Liu, Bingbing, and Cui, Tian, E-mail: cuitian@jlu.edu.cn. Sat . "Pressure-induced structural transformation of CaC{sub 2}". United States. doi:10.1063/1.4948705.
@article{osti_22658018,
title = {Pressure-induced structural transformation of CaC{sub 2}},
author = {Wang, Lu and Huang, Xiaoli and Li, Da and Huang, Yanping and Bao, Kuo and Li, Fangfei and Wu, Gang and Liu, Bingbing and Cui, Tian, E-mail: cuitian@jlu.edu.cn},
abstractNote = {The high pressure structural changes of calcium carbide CaC{sub 2} have been investigated with Raman spectroscopy and synchrotron X-ray diffraction (XRD) techniques in a diamond anvil cell at room temperature. At ambient conditions, two forms of CaC{sub 2} co-exist. Above 4.9 GPa, monoclinic CaC{sub 2}-II diminished indicating the structural phase transition from CaC{sub 2}-II to CaC{sub 2}-I. At about 7.0 GPa, both XRD patterns and Raman spectra confirmed that CaC{sub 2}-I transforms into a metallic Cmcm structure which contains polymeric carbon chains. Along with the phase transition, the isolated C{sub 2} dumbbells are polymerized into zigzag chains resulting in a large volume collapse with 22.4%. Above 30.0 GPa, the XRD patterns of CaC{sub 2} become featureless and remain featureless upon decompression, suggesting an irreversible amorphization of CaC{sub 2}.},
doi = {10.1063/1.4948705},
journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 19,
volume = 144,
place = {United States},
year = {2016},
month = {5}
}