Premium
Experimental and computed HREM images of the structure and defects in gadolinium silicate
Author(s) -
Nissen H.U.,
Kumao A.,
YläJääski J.,
Wessicken R.
Publication year - 1982
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889882011789
Subject(s) - gadolinium , materials science , monoclinic crystal system , silicate , tilt (camera) , stoichiometry , resolution (logic) , electron microscope , image contrast , contrast (vision) , crystallography , optics , crystal structure , chemistry , physics , geometry , mathematics , organic chemistry , artificial intelligence , computer science , metallurgy
Monoclinic Gd 2 SiO 5 has been investigated by high‐resolution electron microscopy (HREM) at 100 kV. Structure images are observed in the [100] and [001] projections and calculations of the image contrast using the multislice approximation are carried out to interpret the observations. For thin samples the image fit is improved by Fourier filtering of the observed images. For thicker samples the fit is found to be very sensitive to small tilt deviations of the zone axis to the electron beam. For defects observed in a fast‐cooled specimen, a model in which Gd atoms replace Si atoms in segments along the (100) plane is proposed and tested by contrast calculations. These defects may be one of the reasons for deviations from stoichiometry as frequently observed in rare‐earth silicates.