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High‐pressure neutron diffraction study of Si 2 N 2 O
Author(s) -
Srinivasa S. R.,
Cartz L.,
Jorgensen J. D.,
Worlton T. G.,
Beyerlein R. A.,
Billy M.
Publication year - 1977
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s002188987701317x
Subject(s) - neutron diffraction , orthorhombic crystal system , bond length , tetrahedron , molecular geometry , compressibility , anisotropy , crystallography , diffraction , materials science , lattice (music) , chemistry , condensed matter physics , crystal structure , thermodynamics , physics , optics , molecule , organic chemistry , acoustics
The lattice parameters, bond lengths and bond angles of Si 2 N 2 O have been determined at pressures up to 23 kbar by time‐of‐flight neutron diffraction. The average compressibility coefficients of the orthorhombic structure are K a = 21 (2), K b = 34 (2), K c = 25 (2) and K ν = 79 (4) x 10 −5 kbar −1 , though the anisotropy is more pronounced at lower pressures with Ka (at zero pressure) estimated to be 10 (8) × 10–5 kbar −1 . The major contribution to the compression is a cooperative rotation of adjacent SiN 3 O tetrahedra brought about by a decrease in the Si–O–Si bond angle. The shortening of one Si–N bond within each tetrahedron further enhances the compression, especially along the b direction.