Structure determination of the zeolite IM-5 using electron crystallography
2010 (English)In: Zeitschrift fur Kristallographie, ISSN 0044-2968, Vol. 225, no 03-feb, 77-85 p.Article in journal (Refereed) Published
The structure of the complex zeolite IM-5 (Cmcm, a = 14.33(4) angstrom. b = 56.9(2) angstrom, c = 20.32(7) angstrom) was determined by combining selected area electron diffraction (SAED), 3D reconstruction of high resolution transmission electron microscopy (HRTEM) images from different zone axes and distance least squares (DLS) refinement. The unit cell parameters were determined from SAED. The space group was determined from extinctions in the SAED patterns and projection symmetries of HRTEM images. Using the structure factor amplitudes and phases of 144 independent reflections obtained from HRTEM images along the ,  and  directions, a 3D electrostatic potential map was calculated by inverse Fourier transformation. From this 3D potential map, all 24 unique Si positions could be determined. Oxygen atoms were added between each Si-Si pair and further refined together with the Si positions by distance-least-squares. The final structure model deviates on average 0.16 angstrom for Si and 0.31 angstrom for O from the structure refined using X-ray powder diffraction data. This method is general and offers a new possibility for determining the structures of zeolites and other materials with complex structures.
Place, publisher, year, edition, pages
2010. Vol. 225, no 03-feb, 77-85 p.
Electron crystallography, Zeolites, Structure determination, HRTEM images, Structure phases and amplitudes
IdentifiersURN: urn:nbn:se:su:diva-50501DOI: 10.1524/zkri.2010.1204ISI: 000276505200005OAI: oai:DiVA.org:su-50501DiVA: diva2:383545
authorCount :72011-01-052010-12-282011-01-05Bibliographically approved