Effects of Eu2O3 on liquid–liquid phase separation of PbO–B2O3, BaO–B2O3 and SrO–B2O3 glasses

The effects of Eu2O3 on liquid–liquid phase separation were studied in the RO–B2O3–Eu2O3 (R represents Pb, Ba or Sr) systems. The results from the in situ observation of the phase separation showed that, in every case, Eu2O3 addition increased the immiscibility temperatures and the effect was more pronounced as the RO content decreased. The Eu distribution in the phase-separated microstructure was examined with an electron probe microanalyser (EPMA) and a field emission scanning electron microscope (FE-SEM) with an energy dispersive X-ray spectrometer (EDS). It was found that the Eu dissolved preferentially in the RO-rich phase droplets with a uniform distribution. A comprehensive account for these effects of Eu2O3 on both the immiscibility temperature and the microstructure was given by considering the RO–B2O3–Eu2O3 ternary phase diagram. For the SrO–B2O3–Eu2O3 system, the Eu2O3 concentration in the droplets was measured with EDS analysis to be found adjustable by changing batch composition.