ISSN:
0020-7608
Keywords:
low-temperature superconductors
;
tight-binding energy-band calculations
;
superconducting transition temperatures
;
chemical bondings
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In the present article, the electronic energy-band structures of 20 series of low-temperature superconductors were investigated employing the tight-binding method within the extended Hückel approximation. The energy bands, the densities of states, and the crystal orbital overlap populations of them are discussed. It is found that, for the crystals in the same series with the same structure type and the component elements in the same group of the periodic table, their overall energy-band structures are similar to each other. The analysis of their chemical bondings shows that the stronger bonding is generally correlated with the lower superconducting transition temperature to some extent. The higher Tc's of 4d metals or compounds relative to those of the corresponding 5d crystals are mainly due to the difference of the electronegativities of metal atoms, while the steric effects play a more important role in the higher Tc of 4d crystals than do those of the corresponding 3d crystals. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 64: 459-472, 1997
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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