COMPARISON OF THE OXYGEN DIFFUSION IN Y1BA2CU3OY BULK MATERIALS AND THIN-FILMS

The kinetics of oxygen diffusion was investigated in Y1Ba2Cu3OY, bulk material and laser ablated thin films on MgO. From isothermal annealin g experiments in different oxygen partial pressures the diffusion coef ficients, activation energies and time-temperature-transformation (TTT ) diagrams were determined and discussed in regard to the oxygen conte nt and the different microstructure of the bulk pellets and the thin f ilms. Diffusion coefficients for the oxygen diffusion in the bulk mate rial of between 1.10(-12) and 2.10(-10) cm2/s were determined by therm ogravimetric measurements in the temperature range of 300-degrees-C to 700-degrees-C. Within the same temperature region in the laser ablate d films (T(c) = 92 K, j(c)(77 K) = 3 . 10(6) A/cm2) diffusion coeffici ents of between 3 . 10(-15) to 3 .10(-12) cm2/s were obtained by in-si tu resistance measurements. In both materials the activation energies for the oxygen diffusion decrease with decreasing oxygen content.