Effect of Simultaneous Nucleation and Crystal Growth on DSC Crystallization Peaks of Glasses

Abstract

In this study, the change of the height of the crystallization peak, (δT)p, and the reciprocal of the crystallization peak temperature, 1/Tp, were investigated as a function of nucleation heat‐treatment time for two silicate glasses: (2BaO·TiO2·2SiO2—B2TS2) and lithium disilicate (Li2O·2SiO2—LS2). Then, monolithic pieces were heat‐treated in a differential scanning calorimetry furnace. The results demonstrated that these glasses behave similarly with respect to peak crystallization temperature, i.e., 1/Tp decreases with the heating rate for nucleation (φn). However, the results with B2TS2 samples demonstrated that (δT)p increases with rising heating rates for nucleation (shorter nucleation heat treatment times), φn, whereas (δT)p was found to decrease with φn in the LS2 specimens. This unexpected behavior is attributed to the extensive overlapping of the I(T) and U(T) curves shown by fresnoite glass.

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

“…In fact, this dependence is a direct result of a higher concentration of nuclei, due to a longer time for nucleation at lower heating rates, which results in the shift of the onset of crystallization toward lower temperatures. This behavior is consistent with theoretical 19,20 and experimental 15,21 investigations. If one considers the volume of nuclei negligible, the area of the peak obtained at different heating rates should be constant since it is representative of the heat of crystallization.…”

“…In this regard, several models based on Equation 1 have been proposed and successfully applied to characterize the kinetics of glass crystallization 9,10,[13][14][15] . If one differentiates Equation 1 with respect to t and applies the logarithm, it is possible to obtain the following expressions:…”

Influence of Particle Size on Nonisothermal Crystallization in a Lithium Disilicate Glass

“…In agreement with previous studies, the results illustrated in Fig. show that 1/ T p increases as the heating rate decreases for all glass particles.…”

“…show that 1/ T p increases as the heating rate decreases for all glass particles. Nevertheless, in contrast with these same authors, (δ T p ) increased as the heating rate increased.…”

“…Depending on the overlapping degree of the I ( T ) and U ( T ) curves, these parameters are proportional to the number of nuclei that are formed during the nucleation regime, as demonstrated by Ref. .…”