Analysis of crystal growth kinetics in undercooled melts by infrared thermography

A new experimental approach based on infrared thermography is proposed in this paper for studying crystal growth kinetics in undercooled melts. The crystallisation of a thin sample of an undercooled melt at constant bulk temperature is induced by a small crystal seed and the growth of the solid phase is observed using infrared camera. The recorded thermal images allow determining the position of crystallisation front at any time, the velocity of advancement of the front at any point and time, and the temperature at the points of the interface at any time. Contrary to experimental techniques based on optical microscopy or video cameras, infrared thermography provides detailed analysis of the interface temperature which is essential when discussing the temperature dependence of experimentally determined growth rates. The appropriateness of infrared thermography for crystal growth kinetics analysis is illustrated through the experimental analysis of erythritol crystallisation.