Theoretical analysis of relative changes of the Hruby, Weinberg, and Lu–Liu glass stability parameters with application on some oxide and chalcogenide glasses

This paper establishes relations between the magnitudes of relative changes of the Hruby (KH), Weinberg (KW) and Lu–Liu (KLL) parameters and differences when moving from one glassy system to another. The parameters KH, KW and KLL are expressed using the reciprocal value of the reduced glass transition temperature (Tm/Tg) as well as the ratio of the crystallization temperature and glass transition temperature (Tc/Tg). The obtained expressions show that all three parameters are in correlation with the mentioned ratios of temperatures. Hence, the number of independent variables by which KH, KW and KLL are expressed is reduced from three to two. That way we can present their functional dependence in the form of three-dimensional graphs. The goal of this paper is to ascertain which of the three parameters has the most relative change when moving from one glassy system to another i.e. which one is the most sensitive. The expressions were derived for the relative changes of these parameters, i.e. for dKH/KH, dKW/KW and dKLL/KLL. We found that the mutual relations between the magnitude of the change of the ratios of Tc/Tg and Tm/Tg determine the order of the values of dKH/KH, dKW/KW and dKLL/KLL. If the relative change of the ratio of the crystallization temperature and glass transition temperature is greater than the change of the reciprocal value of the reduced glass transition temperature, the greatest relative change will be of the parameters KH and KW, in this order. In the opposite case, greater relative change will be in KW than in KH. In both cases, the relative change of the parameter KLL is smallest. This affects the value of the free term in all relations of linear dependencies between the critical cooling rate i.e. ln q and GS parameters. Our tests on two series of oxide glasses and one series of chalcogenide glasses show full agreement with all the results of this theoretical study.