X-RAY DIFFRACTION STUDY ON THE CRYSTAL STRUCTURE OF Sm1+xBa2−xCu3O7−y

Crystal structures in solid solution of Sm1+xBa2−xCu3O7−y (X = 0 - 0.4) have been investigated by Rietveld analysis of X-ray powder diffraction data. The structure changes from orthorhombic to tetragonal at x=0.2. With the increase of x, Tc decreases monotonically from 90 K and the compound becomes semiconducting at x=0.4.