Electronic structure and charge distribution in DyBa2Cu3O7: The ab initio approach

The full-potential linearized augmented plane wave (FP-LAPW) method was used for spin-polarized electronic structure calculations of stoichiometric DyBa2Cu3O7 (Dy123) superconductor. The generalized gradient approximation plus Hubbard correction (GGA + U) was employed for Dy 4f electrons. The reference calculations of YBa2Cu3O7 (Y123) were carried out in the spin-polarized mode to enable direct comparison. The determined total and atomic-projected densities of states (DOS), as well as charge distribution and on-site magnetic moments were analyzed and compared in detail. It was shown that in Dy123 system DOS in the close vicinity of the Fermi level is higher than in Y123. Also more efficient transfer of charge from CuO2 planes was noticed in Dy123. The strongly localized magnetic spin moment of Dy is responsible for relatively weak magnetic interactions in the system, mostly in the CuO2 planes. The obtained computational results are in agreement with the reported good superconducting properties of DyBa2Cu3O7 compound. (C) 2009 Elsevier B.V. All rights reserved.