Remarkable influence of heat treatment on the structural and superconducting properties of (Y_1–xPr_x)(BaSr)Cu₃O_6+z

Abstract

We report here on the preparation, X-ray diffraction (XRD), Seebeck effect, AC magnetic susceptibility, resistivity measurements and effect of heat treatments in the high T c superconductor (Y 1-x Pr x )(BaSr)Cu 3 O 6+z . Each sample was subject to two types of heat treatment: oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. When x increase, the oxygen content (6+z) of the samples decrease slightly from 6.9 to 6.8 as determined by our iodometry measurements. The orthorhombicity ε = (b-a)/(b+a) decreases to zero at