Crystal structure and thermal expansion of. cap alpha. -SiO/sub 2/ at low temperatures

Journal Article · Fri Jan 01 04:00:00 EST 1982 · AIP Conf. Proc.; (United States)

DOI:https://doi.org/10.1063/1.33664· OSTI ID:6488140

Lager, G A; Jorgenson, J D; Rotella, F J

The crystal structure of ..cap alpha..-SiO/sub 2/ (low-quartz) has been refined at 296/sup 0/, 78/sup 0/ and 13/sup 0/K from time-of-flight neutron powder diffraction data. The major effect of temperature from 396/sup 0/ to 78/sup 0/K is a nearly rigid body rotation of the SiO/sub 4/ tetrahedra about the two-fold axis of symmetry. Below 78/sup 0/ the mechanism of thermal expansion is tetrahedral distortion rather than rotation. When compared to published thermal expansion data, the unit cell expansion at low temperatures exhibits a pronounced nonlinearity which can be ascribed to the invariance of the intertetrahedral (Si-O-Si) angle.

• Research Organization: Univ. of Louisville, KY
• OSTI ID: 6488140
• Journal Information: AIP Conf. Proc.; (United States), Journal Name: AIP Conf. Proc.; (United States) Vol. 89; ISSN APCPC
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
EXPANSION
EXPERIMENTAL DATA
INFORMATION
LATTICE PARAMETERS
LOW TEMPERATURE
MINERALS
NEUTRON DIFFRACTION
NUMERICAL DATA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
QUARTZ
SCATTERING
SILICON COMPOUNDS
SILICON OXIDES
TEMPERATURE DEPENDENCE
THERMAL EXPANSION
TIME-OF-FLIGHT METHOD