Influence of Co Doping on the Zn Distribution in Nd1.05Ba1.95Cu3-xZnx</su b>Oz

초록

The structural effects of Zn doping and Zn. Co co-doping in Nd1.05Ba1.95Cu3Oz, have been investigated by using neutron diffraction. The Zn atoms are found to occupy exclusively the planar sites in Nd1.05Ba1.95Cu3ZnxOz, samples with x <= 0.4. An orthorhombic-to-tetragonal transition behavior was observed in the Nd1.05Ba1.95Cu3-xZnxOz (x = 0-0.6) system, while a tetragonal-to-orthorhombic transition was observed in the Nd1.05Ba1.95Cu2.8-xZnx Co0.2Oz = 0-0.6) system as the Zn doping content x increases. A comparative analysis of the structural behavior of Nd1.05Ba1.95Cu3-xZnxOz and Nd1.05Ba1.95Cu2.8-xZnx Co0.2Oz (x = 0, 0.2, 0.4, 0.6) samples showed that the Co doping can induce an increase in Zn occupancy at the Cu(l) sites as the Zn doping concentration increases above x = 0.4, implying that the distribution of Zn ions between the chain and planar sites can be tuned by the Co substitution for the chain Cu sites.

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