Single Crystal Growth of Cuprate Superconductor (Lu${}_{0.8}$Nd${}_{0.2}$)Ba${}_2$Cu${}_4$O${}_8$ by KOH Flux Method

Abstract

Single crystals of Nd-substituted LuBa${}_2$Cu${}_4$O${}_8$ were successfully grown by the KOH flux method. The single phase of Lu${}_{1-x}$Nd${}_x$Ba${}_2$Cu${}_4$O${}_8$ [(Lu,Nd)124] formed at $x=0.2$. The compound crystallized as orthorhombic Ammm structure with lattice constants of a = 3.835(3) Å, b = 3.879(2) Å and c = 27.195(6) Å. Single crystal structural analysis demonstrated that the Nd ion partially occupied the Lu site. The (Lu,Nd)124 exhibited the superconducting transition at ~75 K in the magnetic susceptibility and resistivity. The $T_c$ and the c-axis of the (Lu,Nd)124 corresponded to Tm124. These results indicate that RE124 equivalent to the one composed of single RE element is obtained by combination of two RE elements.

12 pages, 5 figures