Influence of Processing Conditions on the Microstructure and Physical Properties in Infiltration Growth Processed Mixed REBCO Bulk Superconductors.

In this paper, we investigated the effect of liquid phase (LP) source mass on crystal growth, structure, microstructure, and magnetic properties of infiltration growth processed (Gd, Dy)Ba2Cu3 $\text{O}_{{\rm{7}-\rm{x}}}$ ((Gd, Dy)BCO) bulk superconductors. The mixture of Er-123 + Ba3Cu5O8 (035) was chosen as the LP source and the ratio of 211: LP mass (wt%) was varied between 1:1 and 1:1.5. All samples were crystallized in (00l) direction; however, the supply of excess liquids for (Gd, Dy)BCO sample exhibited nonsuperconducting phases. As LP mass increased, the nonsuperconducting inclusions had refined largely due to the availability of a sufficient amount of liquids for peritectic reaction. The 211: LP mass ratio of 1:1.4 was found to be the best relation. The onset of superconducting critical temperature was not influenced by the LP mass. However, the critical current density was gradually improved with the increase in LP mass. The possibilities for further enhancement of physical properties are discussed. [ABSTRACT FROM AUTHOR]