Correlation between maximum crystal growth rate and glass transition temperature of silicate glasses

Recent publications demonstrate that the maximum homogeneous nucleation rates, I max, of silicate glasses strongly diminish with the reduced glass transition temperature, T gr (= T g/ T m/L, where T g is the glass transition temperature and T m/L is the melting point or liquidus temperature). In addition, the critical cooling rates for metallic glass formation, R c, also drop with rising T gr. From these empirical observations as well as from theoretical considerations, it is expected that the maximum crystal growth rates, U max, also depend on T gr. In this paper we test and confirm this assumption by plotting experimental U max vs. T gr for 20 silicate glasses, and then use the most common crystal growth model – screw dislocation growth – to calculate and compare maximum experimental growth rates with theoretical predictions. Despite several assumptions made for the calculations, there is good agreement between theory and experiment, both in the magnitude of U max( T gr) and in the temperature of the maximum crystal growth rate, T max U . These findings indicate that the screw dislocation growth model is a good approximation to describe crystal growth in silicate glasses.