Synthesis of highly pure YBa2Cu3O7-gd superconductors using a colloidal processing technique

This paper reports the high Tc superconducting oxide YBa2Cu3O7-δ synthesized by a simple colloidal sol-gel precursor technique based on citrate complexes uniformly dispersed into ethylene glycol/H2O. The main advantages of the present technique include eliminating steps such as centrifugation, filtration, washing or pH-control in producing precursors and also a few times shorter calcination and sintering time in forming single-phase superconducting material. Both resistivity and magnetic susceptibility measurements have shown sharp superconducting transitions without any indication of two-phase character or the presence of impurity phases