Study of Al-Cu Hume-Rothery alloys and their relationship to the electronic properties of quasicrystals
The stability of quasicrystals is related to the Hume-Rothery mechanism known to take place in many intermetallics, especially Al-Cu alloys. In order to assess to what extent the electronic density of states in aperiodic Al-Cu-Fe compounds is sensitive to Hume-Rothery stabilization, we present exper...
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Published in | Journal of physics. Condensed matter Vol. 10; no. 19; pp. 4231 - 4244 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Bristol
IOP Publishing
18.05.1998
Institute of Physics |
Subjects | |
Online Access | Get full text |
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Summary: | The stability of quasicrystals is related to the Hume-Rothery mechanism known to take place in many intermetallics, especially Al-Cu alloys. In order to assess to what extent the electronic density of states in aperiodic Al-Cu-Fe compounds is sensitive to Hume-Rothery stabilization, we present experimental measurements by soft x-ray emission and absorption spectroscopies of the aluminium electronic states in a series of Al-Cu crystalline compounds. Some of them, like icosahedral Al-Cu-Fe, are characterized by nearly spherical Brillouin zones. We observe the opening of a narrow but definite pseudo-gap in such Al-Cu compounds. We point out a strong interaction between Cu d states and the Al states in the middle of the valence band which is well described by a Fano-like effect. Some other characteristic features of our spectra are interpreted on the basis of band structure calculations. A comparison to previous data published for quasicrystalline and approximant phases stresses the importance for the stability of these compounds of sp-d hybridization at the Fermi level. It also leads to the conclusion that the effect of Hume-Rothery interaction is dramatically enhanced by the hierarchical structure of quasicrystals rather than by the almost spherical shape of the Brillouin zone. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0953-8984 1361-648X |
DOI: | 10.1088/0953-8984/10/19/011 |