Thermal Perturbations at Crystal Nucleation in Glass-Forming Liquids

Abstract

Understanding the processes occurring during the nanocrystallization of glass-forming liquids is important for creating artificial nanostructures for various applications. In this article, local thermal perturbations in supercooled glass-forming liquids and polymers during the nucleation of a crystalline phase are studied. To describe the thermal response of supercooled glass-forming liquids, an integro-differential heat equation with dynamic heat capacity is used. We have found that the effect of the dynamic heat capacity is significant for fast local thermal perturbations that arise in the early stages of crystal nucleation in glass-forming liquids and polymers. It has been established that local temperature perturbations during the nucleation of crystals in silicate glasses and polymers can change the nucleation rate by 2–5 orders of magnitude. The knowledge gained can be useful for the technology of artificial microstructures and advanced materials.

Temperature Relaxation in Glass-Forming Materials under Local Fast Laser Excitations during Laser-Induced Microstructuring

“…The effect of the long-term relaxation of dynamic heat capacity significantly affects the dynamics of local temperature changes T(t, r) [68,69]. In turn, the rate of change in local temperature T(t, r) can significantly affect the microstructuring of glass-forming materials [19,37,43,44,70]. An experimental study of the dynamics of the temperature distribution T(t, r) inside a glass matrix under the action of fast laser thermal perturbations is very difficult.…”

“…In the first part of the article, the heat equation with dynamic heat capacity c dyn (t) is considered. An analytical solution to this equation in general form was presented in our previous work [69], and then this method was applied to describe local thermal disturbances in supercooled glass-forming liquids and polymers during the nucleation of the crystalline phase [70]. We are currently using this method to study the rate of temperature change R(t, r) inside glasses under local fast laser excitations during laserinduced microstructuring.…”