Peierls or Jahn-Teller effect in endohedrally doped silicon clathrates: An EXAFS study
- 15 June 2000
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 61 (24), 16550-16560
- https://doi.org/10.1103/physrevb.61.16550
Abstract
The effect of doping silicon clathrate structures with sodium atoms has been investigated experimentally by x-ray photoemission and x-ray absorption spectroscopies. Both techniques reveal a poor screening of the sodium atoms inside the silicon cages. We also discuss the sodium state that is intermediate between the metal-like and the atomlike ones. These results are in agreement with theoretical predictions of Demkov et al. and Smelyansky and Tse. In addition, the fine analysis of the extended x-ray absorption fine structure region reveals unambiguously a large displacement Å) of the sodium atom with respect to the center of the silicon cage. This displacement is higher than the one predicted by a simple Jahn-Teller effect and is discussed in terms of sodium pairing. The formation of dimers with covalent bonding is compared to the Peierls distortion in a monodimensional network.
Keywords
This publication has 43 references indexed in Scilit:
- Analytical predictions for the magnetoelectric coupling in piezomagnetic materials reinforced by piezoelectric ellipsoidal inclusionsPhysical Review B, 1998
- Raman scattering of silicon clathratesPhysical Review B, 1998
- Superconductivity in the Silicon Clathrate Compound (Na,Ba)SPhysical Review Letters, 1995
- Crystallization and phase transitions in C60Applied Physics Letters, 1992
- Helical microtubules of graphitic carbonNature, 1991
- Superconductivity at 28 K inPhysical Review Letters, 1991
- Superconductivity at 18 K in potassium-doped C60Nature, 1991
- Solid C60: a new form of carbonNature, 1990
- Sur une nouvelle famille de clathrates minéraux isotypes des hydrates de gaz et de liquides. Interprétation des résultats obtenusJournal of Solid State Chemistry, 1970
- Clathrate Structure of Silicon Na 8 Si 46 and Na
x
Si 136 ( x < 11)Science, 1965