Moessbauer study of the effect of oxygen stoichiometry on the high T/sub c/ superconductor Y1Ba2(Cu/sub 0.97/Fe/sub 0.03/)3O/sub 7-x/

The Moessbauer effect of oxygen-depleted YBa2Cu3O/sub 7-x/ and PrBa2Cu3O/sub 7-x/ doped with 3% 57Fe has been investigated at room temperature. A manifold of quadrupole-split spectra has been found, whose parameters are in general agreement with those found by other workers. In addition, the Moessbauer spectra show that a fraction of the Fe sites develop magnetic order at room temperature when the oxygen content is reduced. It is demonstrated that the observed asymmetries in the Moessbauer spectra can be the result of a preferential alignment of the platelike crystallites that arises during the normal sample preparation process. The tendency to bond with the oxygen atoms is presumed to be responsible for the discreteness of the Moessbauer spectra as a function of oxygen depletion