MICROGRAPHICAL PHASES IDENTIFYING IN THE BI2O3-SRO-CAO-CUO SYSTEM

For the Bi2O3-SrO-CaO-CuO quaternary system, in both the Majewski and Strobel papers, the superconducting phase formation, the transformatio ns during their formation and the other coexisting phase were determin ed in the temperature range of 820 to 1100 degrees C. The equilibrium lines were drawn on the basis of the turning points which were obtaine d by means of thermogravimetric and diffraction methods. In this case, the equilibrium line drawing could be non synonymous. We experienced that for correct description of the system also the microstructure exa mination should be applied in addition to this analytical techniques. The room microstructure of an alloy is the result of the transformatio ns which occurred during cooling from the temperature of processing. T he aim of this investigation was phase identification in the Bi-Sr-Ca- Cu-O system, as proposed by Strobel et al., by means of analytical and micrographical methods.