PHASE-STRUCTURE OF THE MIXED-PHASE SUPERCONDUCTING CERAMICS WITH STOICHIOMETRIC COMPOSITION YTEXBA4CU6OY

Previously we have reported that with the addition of Te, ceramics with nominal composition YTexBa4Cu6Oy contain at least two phases: YTex1Ba2Cu3Oy and YTex2Ba4Cu5Oy. A more detailed X-ray analysis-reveals in this investigation that yet two more phases exist in the YTe(x)-146 sample. These two phases, one superconducting, called the Y-111', and the other, non-superconducting, called Y-NSC, are found in samples prepared using the same heating processes and with the predetermined composition YTe0.1Ba1.1Cu1.2Oy. The various volume fractions of the above stated four constituent phases are calculated quantitatively employing our X-ray diffraction data for samples with various amounts of Te. These volume fractions appear to be sensitive to the amount of Te contained in the sample. The lattice constants of the crystals for various phases are determined for different Te amounts,