APPLICATION OF THE RIETVELD METHOD IN THE STUDY OF THE REACTION OF FORMATION OF Y2BACUO5

Quantitative phase analysis of materials can be carried out by X-ray d iffraction using the Rietveld method. However, limitations involving a morphous phases are often found. When solid-state reactions are handle d, the chemical conservation law introduces constraints to phase weigh t-fraction changes. These constraints can then be used, together with diffraction data, to give the real material composition, even when som e of the phases involved are partially or totally amorphous. This proc edure is applied here for the Y2BaCuO5 formation reaction.