The influence of local structure on superconductivity in Fe0.5Cu0.5Ba2YCu2O7.41: a Mössbauer effect study

In this paper, the Mössbauer effect of the Fe0.5Cu0.5Ba2YCu2O7.41 superconductor with Tc = 80 K synthesized at 1000 °C at high pressure of 6 GPa was reported. Results indicate that the high-pressure synthesis makes only a slight amount of Fe located at Cu(2) sites migrate to Cu(1) sites and there is no obvious magnetic pair-breaking effect induced by Fe located at Cu(2) sites. In addition, the high-pressure synthesis changed fourfold coordinated Fe to fivefold coordinated Fe in the chains. We argued that the fivefold coordinated Fe in CuOx chains favors the occurrence of superconductivity in Fe0.5Cu0.5Ba2YCu2O7.41 superconductor.