High-resolution sup 27 Al and sup 29 Si MAS NMR investigation of SiO sub 2 -Al sub 2 O sub 3 glasses

Journal Article · Thu May 30 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100164a057· OSTI ID:5979613

Sato, R K; McMillan, P F ^[1]; Dennison, P; Dupree, R ^[2]

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1. Arizona State Univ., Tempe (United States)
2. Univ. of Warwick, Coventry (England)

{sup 27}Al and {sup 29}Si MAS NMR spectra have been obtained for SiO{sub 2}-Al{sub 2}O{sub 3} glasses quenched from the melt at two rates: 10{sup 5}-10{sup 6} {degree}C s{sup {minus}1} (SQ) and 10{sup 2}-10{sup 3} {degree}C s{sup {minus}1} (NQ). TEM experiments detected phase separation in the S{sub 76}A{sub 24}SQ and S{sub 52}A{sub 48} SQ samples but no phase separation for the S{sub 41}A{sub 59} SQ composition. The NQ glasses were phase separated and, in the diffraction TEM experiments, showed diffuse spots indicating microcrystallinity. {sup 27}Al spectra for the SQ glasses show three peaks due to aluminum in 4-, 5-, and 6-coordination, whereas NQ glasses show only peaks associated with aluminum in 4- and 6-coordination. Quantitative results for the {sup 27}Al spectra are discussed. The effect of spin speed on the {sup 27}Al MAS NMR spectra for SQ and NQ samples is demonstrated. Magnitudes of mean quadrupolar coupling constants and mean isotropic chemical shifts have been estimated. {sup 29}Si spectra of SQ glasses reveal a distribution of 4-coordinate Si sites, whereas NQ glasses show two inequivalent 4-coordinate sites.

• OSTI ID: 5979613
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:11; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ALUMINIUM 27
ALUMINIUM COMPOUNDS
ALUMINIUM ISOTOPES
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL SHIFT
COUPLING CONSTANTS
CRYSTAL STRUCTURE
DATA
DISPERSIONS
ELECTRON MICROSCOPY
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
GLASS
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROSCOPY
MICROSTRUCTURE
MINERALS
MIXTURES
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
QUANTITATIVE CHEMICAL ANALYSIS
RESONANCE
SAMPLE PREPARATION
SILICA
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SILICON OXIDES
SPECTRA
STABLE ISOTOPES
TRANSMISSION ELECTRON MICROSCOPY