Electric Polarizability And Average Single Bond Strength Of Ternary Oxide Glasses With High Ti02 Contents Vesselin Dimitrov

Refractive index based optical basicity Λ(no), refractive index based interaction parameter A(no) and average single bond strength BM–O of an averaged cation–oxide ion (M–O) chemical bond have been estimated for Na2O–TiO2–SiO2, BaO–TiO2–SiO2, and BaO–TiO2–B2O3 glasses. It has been found that the decrease in BM–O is accompanied with an increase in optical basicity and a decrease in interaction parameter of the glasses. More acidic glasses with TiO2 contents of 10–20 mol% possess comparatively large BM–O (390–320 kJ/mol) and A(no) (0·19–0·11 Å−3) which indicates the participation of an average oxide ion in more covalent M–BO (bridging oxygen) bonds such as Si–O–Si and B–O–B. The lower values of BM–O (320–270 kJ/mol) and A(no) (0·11–0·07 Å−3) for the glasses with higher TiO2 contents (30–50 mol%) could be attributed to the formation of M–NBO (nonbridging oxygen) or mixed Ti–O–Si and Ti–O–B bonds with increased ionicity. The glasses are basic in nature.