STIMULATED OXYGEN DIFFUSION IN HIGH-TEMPE RATURE SUPERCONDUCTOR VBA2CU3O7-BETA

The dependence of transport properties of single crystals and textured samples of YBa2Cu3O7-delta on the partial oxygen pressure has been in vestigated. Several breaks on the curves of partial oxygen pressure ha ve been established to depend on the Zeebeck coefficients, characteriz ing different velocity of oxygen desorption processes. An anomalous in crease in the electrical conductivity occur at the phase transition of ortho(1) to ortho(2) phase is observed, which sharply increases the o xygen diffusion coefficient. With the aim of obtaining optimum superco nducting parameters special thermocycling methods used permit to short en the duration of oxidation and to reduce the annealing time.