Effects of Ca doping and oxygen ordering in Cu–O chains on the superconducting properties of (CaxLa1−x)(Ba2−x−yLax+y)Cu3O7+d prepared by amorphous metal complex method

摘要: Abstract The role of sintering conditions in synthesis tetragonal superconducting (Ca x La 1− )(Ba 2− − y + )Cu 3 O 7+ d ( =0.0–0.6, =0.25) polycrystalline samples prepared via an amorphous metal complex method was investigated. series sintered at 910, 930 and 950 °C 2 were characterized by XRD, EDS, Raman spectroscopy iodometric titration to establish the structural chemical differences responsible for their different properties determined from AC magnetic susceptibility measurements. We concluded that heat treatment below required preserve high compositional homogeneity initial precursor powder obtain sharp transition final sample. For such quality samples, we also found interesting feature behavior T c vs. Ca concentration, which has not been reported yet. decreased with increasing content started increase above 0.10.