Heat Capacities of Glassy and Liquid As2S3 And As2Se3

摘要

Heat capacities of glassy and liquid As2S3 and As2Se3 have been determined over the respective temperature intervals 180-650K and 180-620K. The heat capacity data indicate an effective Debye Temperature difference of about 100K between the sulfide and selenide glasses, which is approximately the difference expected on the basis of the atomic mass differences of the two compounds. As2Se3 appears to be the first published example of a glass which exhibits the limiting Dulong and Petit heat capacity over a sizeable temperature interval before the onset of the glass transition. The lack of correspondence between T(g) and Debye temperature is of considerable importance with regard to the production of IR-transmitting chalcogenide glasses, since it indicates that one may optimize IR-transmission characteristics by using high atomic mass components without lowering drastically the upper use temperature, i.e., the glass transition temperature. (Author)