TY - JOUR
T1 - Heat capacities and thermal behavior of alkali borate glasses
AU - Uhlmann, D. R.
AU - Kolbeck, A. G.
AU - De Witte, D. L.
N1 - Funding Information:
The authors are happy to acknowledge stimulating discussion with J. T. Fournier, R. R. Shaw and R. J. Landry of the American Optical Company. Financial support for the work was provided by the Advanced Research Projects Agency under Contract ARPA SD-90 and by the Undergraduate Research Opportunities Program at M.LT.
PY - 1971/5
Y1 - 1971/5
N2 - The heat capacities of selected glasses in the five alkali borate systems have been measured over a range of high temperatures which includes the respective glass transition regions. The heat capacities per gram atom at 350°K show little variation with composition while those at the low temperature ends of the glass transition, Tg-, show some systematic variations. When compared with the respective 3R values, the heat capacities at Tg- range from about 0.75 for B2O3 to values in excess of unity for various alkali borate compositions. The present data on heat capacity have been combined with previous data on the elastic moduli, densities and thermal expansion coefficients to evaluate the Grüneisen constant, γ, for each composition for temperatures around ambient. For B2O3, γ has a low value of about 0.25. It decreases with additions of Li2O and increases with additions of the other alkali oxides.
AB - The heat capacities of selected glasses in the five alkali borate systems have been measured over a range of high temperatures which includes the respective glass transition regions. The heat capacities per gram atom at 350°K show little variation with composition while those at the low temperature ends of the glass transition, Tg-, show some systematic variations. When compared with the respective 3R values, the heat capacities at Tg- range from about 0.75 for B2O3 to values in excess of unity for various alkali borate compositions. The present data on heat capacity have been combined with previous data on the elastic moduli, densities and thermal expansion coefficients to evaluate the Grüneisen constant, γ, for each composition for temperatures around ambient. For B2O3, γ has a low value of about 0.25. It decreases with additions of Li2O and increases with additions of the other alkali oxides.
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U2 - 10.1016/0022-3093(71)90043-3
DO - 10.1016/0022-3093(71)90043-3
M3 - Article
AN - SCOPUS:0001218483
VL - 5
SP - 426
EP - 443
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
IS - 5
ER -