Unique physical properties and fragility of 50CuO x-50P 2O 5 glasses

Abstract

50CuO x -50P 2O 5 glasses with different copper valence states (0 < Cu +/(Cu 2+ + Cu +) < 0.61) were prepared by adding glucose during glass melting, and some physical properties and fragility of these glasses were examined. The density of 50CuO x -50P 2O 5 glasses decreases linearly with increasing Cu + content from 3.18 to 3.01 g/cm 3. Although the glass transition temperature decreases with increasing Cu + content from 437 to 196°C, the viscosity and the activation energy for viscous flow also decrease with increasing Cu + content. From the concept of fragility, it was found that 50CuO x -50P 2O 5 supercooled liquids become strong with increasing Cu + content due to the formation of strong Cu +O bonds. The properties of 50CuO x -50P 2O 5 glasses were compared with those of xNaO 0.5-(50− x)MgO-50P 2O 5 glasses, and the results suggest that the former glasses exhibit unique properties and fragility due to a unique coordination state of Cu +.