Influence of water on the physical properties of calcium aluminate oxide glasses

Calcium aluminate oxide glasses are transparent over wavelengths ranging fr om the near UV to the mid-IR (6 - 7 mu m) and are excellent infrared transm itting materials. In the present paper, the influence of water on the physi cal properties, including density, index of refraction, and sound velocitie s, of three calcium aluminate oxide glasses were studied by IR absorption a nd ultrasonic pulse echo measurements. In the IR spectra, an OH group relat ed absorption peak of around 3440 cm(-1) was observed, and developed as tim e passed. The derived values of the elastic constants were larger than that of pure SiO2 glass. A possible explanation for the experimental observatio ns is discussed in the light of existing theories. (C) 1999 Elsevier Scienc e S.A. All rights reserved.