Preparation and Characterization of the New Y257 Superconductors

Abstract

The new Y257 superconductor in YBaCuO family was synthesized by standard solid state reaction. The Y257 samples were measured the critical temperature (Tc) by the four-probes method that found at 90 K. The XRD technique and FULLPROF program were used to determine the lattice parameters, space group and phase compositions. It was found that the Y257 exhibited in both of superconducting and non-superconducting phase. The Pmmm space group was fit well on superconducting phase with the lattice parameters as a=3.8108 Å, b=3.8544 Å and c=26.4967 Å. The non-superconducting phase exhibited in two space groups of Pccm (a=12.9770 Å, b=20.54780 Å and c=11.3530 Å) and Im-3m (a= 18.2104 Å, b=18.2104 Å and c=18.2104 Å). The peritectic temperature at 976.73°C was measured by differential thermal analysis.