Structure and property of multicomponent germanate glass containing Y2O3

CaO-BaO-Al 2 O 3 -SiO 2 -GeO 2 glasses doped with 0·00-16·67 wt-% Y 2 O 3 have been prepared by conventional melt quenching method. The influence of Y 2 O 3 addition on the properties and structure of the glasses has been investigated. The results show that, with the introducing of Y 2 O 3 , 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 Y 2 O 3 , the bend strength of the glass including 4·76 wt-% Y 2 O 3 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 Y 2 O 3 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.