Bi2Sr2CaCU2Ox glasses with Cu+/Cu(total) ratios from 0.78 to 0.98 were
prepared by adding glucose during glass melting. The density of glass
es decreased linearly with increasing Cu+ content from 6.25 to 6.10 g/
cm3. Viscosity and activation energy for viscous flow decreased rapidl
y with increasing Cu+ content. The structure of these glasses is sensi
tive to Cu+ content, and the excess free volume increases with Cu+ con
tent.