| Autor: |
Zubko, Maciej, Kusz, Joachim, Prodan, Albert, Šturm, Sašo, van Midden, Herman J. P., Craig Bennett, J., Dubin, Grzegorz, Zupankč, Erik, Böhm, Horst |
| Předmět: |
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| Zdroj: |
Acta Crystallographica Section B: Structural Science, Crystal Engineering & Materials; Jun2013, Vol. 69 Issue 3, p229-237, 9p |
| Abstrakt: |
The real crystal structure of the (NbSe4)10/3I charge density wave (CDW) compound is studied by simulation of the X-ray diffuse scattering. The average structure of the low-temperature twinned phase is determined and the phase transition is attributed to the formation of a CDW. The diffuse streaking, present in X-ray diffraction patterns above and below the transition at T = 282 K, is shown to be a projection of diffuse concentric rings perpendicular to the c* direction. The simulated patterns, based on a mismatch model between infinite NbSe4 chains, correlated by I atoms, are in good accordance with the experimental patterns. In addition to the experiments, the electronic properties of the high- and the low-temperature phases are calculated with the extended Hückel tight-binding method. The Fermi surfaces of the average structures above and below the phase transition appear very similar. Their shapes support a nesting instability and a CDW formation. The weak incommensurate CDW satellites, present below the phase transition, are at 100 K properly described by a modulation wavevector q = [0.06 (1), 0, 0.55 (1)]. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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