Kinetics of the sintering of superconducting ceramics YBa 2− xSr xCu 3O 7− y

Abstract

The densification kinetics of ceramics YBa 2− x Sr x Cu 3O 7− y (YBC,YBSC: doped with strontium) was studied at constant heating rate with a dilatometer. The different sintering regimes were clearly detected and analysed tentatively according to the available densification models. The data for the initial and intermediate stages fitted reasonably well with the Johnson and Coble models, and the average activation energies for grain boundary and volume diffusion, were roughly estimated. For YBC compositions, a satisfactory fit with a liquid-phase sintering model was obtained at temperatures higher than about 960°C.