Structure and property of multicomponent germanate glass containing Y2O3

CaO–BaO–Al2O3–SiO2–GeO2 glasses doped with 0·00–16·67 wt-% Y2O3 have been prepared by conventional melt quenching method. The influence of Y2O3 addition on the properties and structure of the glasses has been investigated. The results show that, with the introducing of Y2O3, the density, glass transition temperature and thermal expansion coefficient of the glass increase but the chemical durability declines. In addition, compared with the glass without Y2O3, the bend strength of the glass including 4·76 wt-% Y2O3 increased from 54 to 110 Mpa. The possible mechanism is that yttria acts as a network former in the structure and makes the island shape network unit repolymerisation by forming Ge–O–Y bond. The absorption strength caused by hydroxyl vibration decreased up to completely disappearance as the Y2O3 content increased continuously. The introducing of yttria in the composition causes the conversion from four coordination to higher coordination germanium, which decreases non-bridge oxygen (NBO) and weakens hydroxyl characteristic absorption.