Effect of CuO on the properties of stannous chlorophosphate glasses

The effect of CuO addition on the properties of stannous chlorophosphate glasses has been studied. CuO addition improves the chemical durability of stannous chlorophosphate. Density, hardness, glass transition temperature and softening temperature increase, while thermal expansion coefficient and dissolution rate of the glasses decrease with increasing CuO content. The short-range structure of glasses was examined by X-ray photoelectron spectroscopy (XPS). O 1s and Cl 2p XPS spectra indicate that the relative amount of asymmetric bridging oxygen (P–O–Cu; P–O–Sn) increases, and that the concentration of non-bridging chlorine (P–Cl and Sn–Cl) decreases with increasing CuO content of the glasses. A structural model of Sn–(Cu)–P–O–Cl glasses is proposed to explain the property change due to composition variation.