Influence of the Structural Disorder on the Mössbauer Spectra of YBa2Cu3-yFeyO7-x

Abstract

In the present work the ⁵⁷Fe Mössbauer spectra interpretation on regard to doped YBa₂Cu₃O_7-x samples has been analyzed starting from a more detailed description of the structural disorder existing in its basal plane. Thus, possible fluctuations in the spatial orientation of atomic positions located in the ⁵⁷Fe isotope neighborhood were considered by introducing oxygen clusters located in the reference site neighborhood. The applied calculation algorithm estimate the effective electric field gradient tensor at the reference nuclear positions as the sum of a contribution from the analyzed cluster and another arising from the rest of the atomic positions located in an ideal crystalline lattice. This algorithm allows to reproduce all the observed experimental lines; as well as to study the oxygen content increase and the symmetry change effects in this material samples.