Effect of the substitution of S for Se on the structure of the glasses in the system Ge0.23Sb0.07S0.70−xSex

Glasses in the system Ge-Sb-S/Se, expected to have high nonlinear index, have been elaborated with different S/Se ratio in order to increase the nonlinear optical properties of these glasses. We report results of a systematic study examining the relationship of the physical properties to the structure of the glasses in the system Ge0.23Sb0.07S0.70−xSex with x=0, 0.05, 0.10, 0.20, 0.50 and 0.70 where the substitution of S for Se has been made. The decrease of the glass transition temperature and the increase of the density with the progressive substitution of S for Se have been correlated, in accordance with the red shift of the absorption band gap, to the progressive decrease of corner-sharing GeS4/2 units for 0.050.50.