THE ROLE OF BACO3 IN HIGH-TEMPERATURE SYNTHESIS OF ELECTRONIC MATERIALS

The syntheses of superconducting YBCO powders, prepared by solid state reaction, vacuum pyrolysis of acetates, spray pyrolysis of acetates a nd calcinated oxalates were performed. All of the powders in a paste f orm were deposited on the Al2O3 substrate. After sintering and anneali ng the obtained superconducting YBCO thick layers were examined in dif ferent (CO2 + O-2) atmospheres. The thermogravimetric as well as IR sp ectroscopy and SEM study confirm that on the grain boundaries the BaCO 3 phase is formed. The presence of BaCO3 phase may cause degradation o f superconducting materials.