Properties and structure of copper ultraphosphate glasses

The structures of JcCuO (1 -x)P₂O₅ glasses (03 tetrahedra into a chain-like metaphosphate structure dominated by Q² tetrahedra. IR spectra clearly show two distinct Q³ sites with bands at 1378 and 1306cm ^-1, assigned to P=O bonds on isolated Q³ tetrahedra and P=O bonds on Q_Cu ³ tetrahedra that participate in the coordination environments of the Cu-octahedra, respectively. As CuO content increases, the intensity of the P=O band associated with the Q_Cu ³ tetrahedra increases to a maximum x ∼0.33, then decreases with a concomitant increase of the intensity of the band at 1265cm^-1, due to the asymmetric vibration of the PO₂ groups on Q² tetrahedra. When x > 0.33 the isolated Cu-octahedra begin to share common oxygens to form a sub-network in the phosphate matrix. The effects of glass structure on the glass properties, including density, refractive index, and glass transition temperature, are discussed.