Titelangaben
Lüdecke, Jens ; van Smaalen, Sander ; Spijkerman, Albert ; de Boer, Jan L. ; Wiegers, Gerrit A.:
Commensurately modulated structure of 4Hb-TaSe₂ determined by x-ray crystal-structure refinement.
In: Physical Review B.
Bd. 59
(1999)
Heft 9
.
- S. 6063-6071.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.59.6063
Abstract
The (13√a×13√a×c) superstructure of 4Hb-TaSe₂ at room temperature has been determined by x-ray crystal-structure refinement using (3+2)-dimensional superspace. The resulting modulation has its largest amplitudes for a longitudinal displacement of the Ta atoms in the octahedrally coordinated (T) layers, thus leading to a superstructure of hexagram-shaped clusters containing thirteen Ta atoms each. The atoms in the corresponding planes of Se atoms show a transversal modulation, which can be interpreted as the relaxation of these layers to the modulation of the Ta layers. Forming a similar pattern, modulations were found of the atoms in the layers with Ta in trigonal prismatic coordination (H layers), with amplitudes of about 1/10 of the sizes of the modulations in the T layers. These results confirm the presence of a charge-density wave in the T layers, while the modulations of the H layer can be assigned to elastic coupling between the two types of layers. The observation of nonzero displacements of the atoms of the H layers provides an interpretation for recent observations by scanning tunneling microscope (STM): the superstructure features observed by STM on the H layers is a direct consequence of the atomic displacements in this layer.
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Publikationsform: | Artikel in einer Zeitschrift |
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Begutachteter Beitrag: | Ja |
Institutionen der Universität: | Fakultäten > Fakultät für Mathematik, Physik und Informatik > Fachgruppe Materialwissenschaften > Lehrstuhl Kristallographie Fakultäten > Fakultät für Mathematik, Physik und Informatik > Fachgruppe Materialwissenschaften > Lehrstuhl Kristallographie > Lehrstuhl Kristallographie - Univ.-Prof. Dr. Sander van Smaalen Fakultäten Fakultäten > Fakultät für Mathematik, Physik und Informatik Fakultäten > Fakultät für Mathematik, Physik und Informatik > Fachgruppe Materialwissenschaften |
Titel an der UBT entstanden: | Ja |
Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 530 Physik |
Eingestellt am: | 10 Jun 2016 07:40 |
Letzte Änderung: | 26 Aug 2022 07:01 |
URI: | https://eref.uni-bayreuth.de/id/eprint/32636 |