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Atomistic characterization of structural and elastic properties of auxetic crystalline SiO 2
Author(s) -
Kimizuka Hajime,
Ogata Shigenobu,
Shibutani Yoji
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200572709
Subject(s) - materials science , stishovite , cristobalite , bulk modulus , poisson's ratio , auxetics , elastic modulus , quartz , ab initio , thermodynamics , crystallography , composite material , poisson distribution , chemistry , physics , statistics , mathematics , organic chemistry
The structural and elastic changes with volume expansion in α ‐quartz and α ‐cristobalite, the typical polymorphs of silicon dioxide (SiO 2 ), have been studied through first‐principles calculations using the projector‐augmented‐wave (PAW) method, with particular emphasis on their negative Poisson's ratio behavior under negative pressure. The dominant mechanism of expansion is the increase of the Si–O–Si angles within their crystalline structures, whereas the SiO 4 tetrahedron undergoes only a slight distortion. We provide theoretical ab initio results for a complete set of independent elastic constants of quartz and cristobalite with volume expansion. The present simulations confirm that the negative Poisson's ratio behavior is enhanced in the expansive phases of both polymorphs under negative pressures, with retaining strong elastic anisotropy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)