High-T fullerides
| Autor: | Cristiano C. Bastos, A.C. Pavão, Renato César da Silva |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Ionic radius Methylamine Energy Engineering and Power Technology Ionic bonding Thermodynamics Condensed Matter Physics Alkali metal 01 natural sciences Electronic Optical and Magnetic Materials Electronegativity chemistry.chemical_compound Lattice constant chemistry Chemical bond 0103 physical sciences Molecule Electrical and Electronic Engineering 010306 general physics |
| Zdroj: | Physica C: Superconductivity and its Applications. 561:13-17 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/j.physc.2019.02.001 |
| Popis: | The critical temperature of the fulleride superconductors A2BC60 (A, B = Na, K, Rb, Cs) with the alkali metals solvated with ammonia, methylamine, and water molecules is calculated using a multivariate analysis of the lattice parameter, ionic radius, electronegativity, and other electronic properties obtained from density functional theory calculations. Results are in good agreement with the experimental data both for the alkali-metal fullerides and for the solvated (NH3)4Na2CsC60, (CH3NH2)K3C60 and (NH3)K3C60 compounds. The expansion of the crystalline lattice and the increase of the ionic character of the chemical bonds with solvation of the metal can modify significantly the critical temperature of the material. In the ammoniation of Na2CsC60, there occurs an expansion of the lattice and an increase of the ionic character of the chemical bonds in the material, which increases its critical temperature by about 20 K. Methylamine also can raise the critical temperature but is not as efficient as ammonia. Our results suggest that hydration of Na3C60 leads to the superconducting state and that (H2O)4Cs3C60 is a high-Tc fulleride at 50.9 K. |
| Databáze: | OpenAIRE |
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