Year: 2018
Type: article
Abstract: The defect structure of γ-Al2O3derived from boehmite was investigated using a combination of selected-area electron diffraction (SAED) and powder X-ray diffraction (XRD). Both methods confirmed a strong dependence of the diffraction line broadening on the diffraction indices known from literature. The analysis of the SAED patterns revealed that the dominant structure defects in the spinel-type γ-Al2O3are antiphase boundaries located on the lattice planes (00l), which produce the sublattice shifts {{1}\over{4}}\langle 10{\overline 1}\rangle. Quantitative information about the defect structure of γ-Al2O3was obtained from the powder XRD patterns. This includes mainly the size of γ-Al2O3crystallites and the density of planar defects. The correlation between the density of the planar defects and the presence of structural vacancies, which maintain the stoichiometry of the spinel-type γ-Al2O3, is discussed. A computer routine running on a fast graphical processing unit was written for simulation of the XRD patterns. This routine calculates the atomic positions for a given kind and density of planar defect, and simulates the diffracted intensities with the aid of the Debye scattering equation.
Source: IUCrJ
Institution: TU Bergakademie Freiberg
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,200
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W2904473841