Structure of haloform intercalated C60 and its influence on superconductive properties
| Autor: | Ashfia Huq, Peter W. Stephens, Olle Gunnarsson, Erik Koch, Holger Brumm, Martin Jansen, Robert E. Dinnebier |
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| Rok vydání: | 2002 |
| Předmět: |
Superconductivity
Multidisciplinary Condensed matter physics Chemistry Transition temperature Fermi level Fermi energy Crystal structure Triclinic crystal system Condensed Matter::Materials Science symbols.namesake Crystallography Tight binding X-ray crystallography Physics::Atomic and Molecular Clusters symbols Density of states Surface layer Electronic band structure |
| Zdroj: | Science (New York, N.Y.). 296(5565) |
| ISSN: | 1095-9203 |
| Popis: | CHCl 3 and CHBr 3 intercalated C 60 have attracted particular interest after a superconductivity transition temperature ( T c ) of up to 117 K was discovered. We have determined the structure using synchrotron x-ray powder-diffraction and found that the expansion of the lattice mainly takes place in one dimension (triclinic b axis), leaving planes of C 60 molecules on an approximately hexagonal, slightly expanded lattice. We have performed tight-binding band structure calculations for the surface layer. In spite of the slight expansion of the layers, for the range of dopings where a large T c has been observed, the density of states at the Fermi energy is smaller for C 60 ·2CHCl 3 and C 60 ·2CHBr 3 than for C 60 . This suggests that the lattice expansion alone cannot explain the increase of T c . |
| Databáze: | OpenAIRE |
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