Original scientific paper

Band Structures for Superconductors LnBa₂Cu₃O₇ (Ln = Ho, Er, Tra, Yb)

Li Ming ; Department of Chemistry, Southwest China Normal University, Chongqing 630715, People’s Republic of China

Abstract

Electronic energy band structures for the superconducting system given by substitutions of rare earth cations (Ho,Er,Tm,Yb) for Y in YBa2Cu307 were investigated by employing the EHMO approach based on the tight-binding method. As compared, to the results of YBa2Cu307, the substitutions of the rare earth cations dramatized the degree of complexity of the energy band structures at the Fermi surface and resulted in an increase in the number of bands crossing the Fermi level Ef and electronic densities of states, while those for PrBa2Cu3C>7 decreased. From the energy bands and the electronic densities of states obtained from calculations, it is explained why the substitutions of Ho, Er, Tm and Yb in YBa2Cu3C>7 can still maintain the high superconducting transition temperature Tc, while the substitution of Pr does not.

Keywords

Hrčak ID:

137065

URI

https://hrcak.srce.hr/137065

Publication date:

1.7.1993.

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