Single Crystal Growth of Cuprate Superconductor (Lu0.8Nd0.2)Ba2Cu4O8 by KOH Flux Method

Single crystals of Nd-substituted LuBa2Cu4O8 were successfully grown by the KOH flux method. The single phase of Lu1−xNdxBa2Cu4O8 [(Lu,Nd)124] formed at x = 0.2. The compound crystallized as an orthorhombic Ammm structure with lattice constants of a = 3.835(3) A, b = 3.879(2) A, and c = 27.195(6) A. Single crystal structural analysis demonstrated that the Nd ion partially occupied the Lu site. The (Lu,Nd)124 exhibited a superconducting transition at ∼75 K in the magnetic susceptibility and resistivity. The Tc and the lattice constant c of the (Lu,Nd)124 corresponded to Tm124. These results indicate that an RE124 (RE: rare earth) equivalent to the one composed of a single RE element is obtained by combining two RE elements.