Correlation between thermal expansion coefficient and interionic interaction parameter in ZnO-Bi2O3-B2O3 glasses

The volume thermal expansion coefficients (beta) in 50-300 degrees C of xZnO-yBi(2)O(3)-zB(2)O(3) glasses (x = 10-65, y = 1050, z = 25-60 mol%) were measured and the refractive index-based interionic interaction parameters A(no) were estimated from oxide ion electronic polarizabilities to acquire deeper insight into the relationship between the electronic polarizability and chemical bonding state of oxide glasses. The glasses have relatively large values of beta = 210-289 x 10(-7) K-1 , and the substitution of ZnO for B2O3 and the increase in Bi2O3 content result in an increase in beta. The values of A(n(o)) decrease with the substitution of ZnO for B2O3 and the substitution of Bi2O3 for ZnO. An almost linear correlation was observed between beta and A(n(o)), i.e., the volume thermal expansion coefficient decreases with increases in the interionic interaction parameter. A good correlation was also observed between A(n(o)) and the refractive index-based optical basicity A(n(o)). The interionic interaction parameter is helpful for understanding the chemical bonding state of oxide glasses. (C) 2018 The Ceramic Society of Japan. All rights reserved.