BAO-1 2Y2O3-CUOX EUTECTIC MELTING IN AIR

Eutectic melting in the BaO-1/2Y2O3-CuOx system has been investigated, using three different compositions. Thermal events up to 1100-degrees -C were studied by means of differential thermal analysis/thermogravim etric analysis (DTA/TGA). Phase formation and compositions of melts we re examined using powder X-ray diffraction and scanning electron micro scopy/energy-dispersive X-ray spectrometry (SEM/EDS) of quenched exper iments. The eutectic occurs at 923-degrees +/- 10-degrees-C in CO2- an d H2O-scrubbed air, and the eutectic melt has a Ba:Y:Cu cation ratio o f 23.2(+/-0.5): 0.5(+/-0.1):76.3(+/-1.0). The oxygen content of the qu enched eutectic melt, as determined by hydrogen reduction, indicated t hat nearly all of the copper in the melt was present as Cu+. A topolog ical sequence, based on the X-ray results, is presented which describe s the events immediately following melting.