Growth of R-123 Phase Single Crystal Whiskers

TL;DR

This paper reports the successful growth of R-123 phase single-crystal whiskers using Te- and Ca-doping methods, analyzing their composition, growth conditions, and superconducting properties.

Contribution

It introduces a novel doping method for growing R-123 whiskers from various rare earth elements and characterizes their critical temperatures and post-annealing requirements.

Findings

Whiskers grown at just below peritectic temperatures.

Critical temperatures around 80 K for most whiskers.

Larger R ionic radii require post-annealing in oxygen.

Abstract

Single-crystal whiskers of R1Ba2Cu3Ox (R-123, R= La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu) phase have been successfully grown by the Te- and Ca-doping method. The whiskers were grown from precursor pellets at just below their partial melting (peritectic) temperatures. The nominal composition of the R-123 whiskers is R1+uBa2+vCawCu3Ox (u+v+w=0, w>0) with R and/or Ba sites being substituted by Ca. However, the amount of Te was less than the analytical limit. The critical temperatures of the R-123 whiskers were around 80 K, and among these whiskers those with larger R ionic radii such as Dy, Gd, Eu and Sm require post-annealing in an oxygen atmosphere.