Infrared Spectroscopy of Lead and Alkaline‐Earth Aluminosilicate Glasses

Infrared spectroscopic studies of lead and alkaline‐earth aluminosilicate glasses in the series x MO‐ x Al 2 O 3 (1 ‐ 2 x )SiO 2 M = Mg, Ca, Sr, Ba, and Pb; 0.05 x 0.275] were carried out in the range 2000 to 200 cm −1 . Three major absorption bands were observed in the 1100‐, 800‐, and 500‐cm −1 regions. The frequency and the intensity of the 1100‐cm −1 band varied linearly with composition. For a specific value of x , the changes in the frequency, intensity, and bandwidth of this band decreased in the order Mg > Ca > Sr > Pb > Ba and the apparent disorder in the glass structure, effected by the substitution of aluminum, increased in the direction Mg < Ca < Sr < Ba, with Pb in between Mg and Ca. The force constants and the bond orders of the Si‐O and Al‐O stretching vibrations in each of the glasses increased monotonically as Al/(Al + Si) decreased.