Quantitative estimation of crystallization kinetics in GeGaS and Au‐doped GeGaS glass‐ceramics

Abstract

Ge26.7Ga8S65.3 (GGS) and 0.1% Au‐doped Ge26.7Ga8S65.3 (GGS‐Au) glasses were prepared and annealed at a temperature that is 20 K higher than their respective glass transition temperature in order to create chalcogenide glass‐ceramics. X‐ray diffraction results showed that, thermal annealing can induce large amount of the crystal growth in the pure glass but this can be significantly suppressed by Au doping in the glass, which is in agreement with the previous results. We further employed various calorimetric methods, together with Mauro‐Yue‐Ellison‐Gupta‐Allan viscosity model, to investigate their crystallization kinetics. The crystal growth rate at annealing temperature of 723 K was quantitatively deduced to be 2.5 × 10−8 μm/s in Au‐doped GGS, which is about 20 times slower than that in the pure GGS with a growth rate of 4.7 × 10−7 μm/s.

Single‐run DSC method for determining surface crystal growth rate in glasses generalized for samples of different shapes

“…From Equations ( 4) and (7), it follows that the crystal growth rate can be obtained at each temperature T from a DSC experiment using Eq. (8).…”

“…3 The growth rate of a phase is one of the parameters commonly considered in phase transformation models in all fields of materials science. In the glass field, the crystal growth rate is a key parameter for developing glass ceramics, 1,[4][5][6][7] designing sintering heat treatments to control densification, [8][9][10] calculating critical cooling rates, 11 and understanding fundamentals of glass science. 12,13 The usual method for its determination is to measure the crystal size in samples heattreated for different times at different temperatures.…”