STABILITY ESTIMATION OF YBCO BY STEPWISE XRD AND KINETIC-STUDIES THROUGH TGA

The stability of the high-temperature superconductor YBa2Cu3O7-delta o n treatment with water has been examined and quantitatively determined by XRD, AC magnetic susceptibility measurements and TGA, and by calcu lating the lattice parameters through Cohen's method. The kinetic para meters, viz. activation energy and order of reaction, have been determ ined from the TGA data. Progressively longer treatment results in the degradation of the material, as evidenced by corresponding changes in the values of lattice parameters, changes in orthorhombicity, and a co ntinuous increase in the value of the activation energy. The reaction leading to the decomposition of the material is found to be of first o rder.