Anisotropic compression of a synthetic potassium aluminogermanate zeolite with gismondine topology
Compression behavior of a potassium aluminogermanate with a gismondine framework topology (K-AlGe-GIS) was studied using in-situ high-pressure synchrotron X-ray powder diffraction. In contrast to the potassium gallosilicate analogue (K-GaSi-GIS), no elastic anomaly due to pressure-induced hydration and/or cation relocation was observed in K-AlGe-GIS. The Birch-Murnaghan fit to the pressure-volume data results in a bulk modulus of B{sub 0} = 31(1) GPa. The derived linear-axial compressibilities (i.e., {beta}{sub a} = 0.0065(5) GPa{sup -1}, {beta}{sub b} = 0.0196(4) GPa{sup -1}, {beta}{sub c} = 0.0081(7) GPa{sup -1}) indicate that the b-axis, normal to the 8-ring channels, is about three times more compressible than the a and c axes, parallel to the elliptical 8-ring channels. As a consequence a gradual flattening of the so-called 'double crankshaft' structural building units of the gismondine framework is observed. In K-AlGe-GIS, this flattening occurs almost linear with pressure, whereas it is nonlinear in the GaSi-analogue due to structural changes of the water-cation assembly under hydrostatic pressures.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- DOE - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 991726
- Report Number(s):
- BNL-94181-2010-JA; JSSCBI; R&D Project: LS001; KC0401030; TRN: US1007550
- Journal Information:
- Journal of Solid State Chemistry, Vol. 183, Issue 10; ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Cation-dependent anomalous compression of gallosilicate zeolites with CGS topology: A high-pressure synchrotron powder diffraction study
(Na{sub 4}BH{sub 4}){sup 3+} guests inside aluminosilicate, gallosilicate and aluminogermanate sodalite host frameworks studied by {sup 1}H, {sup 11}B, and {sup 23}Na MAS NMR spectroscopy