Comparison of Au-free versus Au-doped YBa2Cu3O7−δ single crystals: Overdoping and oxygen mobility

Abstract By systematically changing the oxygen concentration of YBa 2 Cu 3 O 7−δ single crystals grown in Au-crucibles, we demonstrate that the incorporated Au-impurities have only a minor effect on the maximum in T c due to overdoping. On the other hand, we demonstrate that the Au-impurities significantly increase the oxygen mobility in the basal planes of oxygen deficient YBa 2 Cu 3 O 7−δ single crystals.