Further investigation of the stabilization of {beta}-cristobalite

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb06956.x· OSTI ID:142234

Thomas, E S; Thompson, J G; Withers, R L ^[1]; Sterns, M ^[2]; Xiao, Yuehui; Kirkpatrick, R J ^[3]

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1. Australian National Univ., Canberra (Australia). Research School of Chemistry
2. Australian National Univ., Canberra (Australia). Dept. of Chemistry
3. Univ. of Illinois, Urbana, IL (United States). Dept. of Geology

Chemical stabilization of {beta}-cristobalite has been achieved using two methods: (1) incorporating ``stuffing`` cations Na, Ca, Cu, and Sr into the cavities in the tectosilicate framework, as previously reported, and (2) without ``stuffing`` cations, by substituting AIPO{sub 4} into the framework. XRD, TEM, FTIR, DSC, and solid-state variable-temperature {sup 29}Si NMR confirm that stabilization occurs by both methods. Dynamic disorder, characteristic of the {beta}-cristobalite structure above the {alpha} {leftrightarrow} {beta} phase transition, was observed via TEM in the NaAlO{sub 2}-, CaAl{sub 2}O{sub 4}-, and CuAl{sub 2}O{sub 4}-stabilized cristobalites at room temperature. For AIPO{sub 4}-stabilized material intergrowths of AIPO{sub 4} regions with a tridymite-type structure suppress the {beta}- {yields} {alpha}-cristobalite phase transition.

• Sponsoring Organization: USDOE
• OSTI ID: 142234
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 1 Vol. 77; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM PHOSPHATES
CALCIUM
COPPER
CRISTOBALITE
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
EXPERIMENTAL DATA
NUCLEAR MAGNETIC RESONANCE
STRONTIUM
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION