Segregation and constitutional supercooling in Nd:YAG Czochralski crystal growth

•A model for prediction of constitutional supercooling in Czochralski configuration is proposed.•Effect of convection on constitutional supercooling is investigated.•A good agreement has been found between the analytical results and experimental data. This article examines the issues of segregation and constitutional supercooling (CSC) in the context of industrial highly-doped Nd:YAG crystal growth. The study involved the growth of several Nd:YAG crystals using Czochralski method, revealing that the heavily Nd3+ doped YAG crystals often cracked during the late stage of shoulder growth. At this stage, the solid–liquid interface instability was observed, and it was found that CSC led to temperature fluctuations, ultimately causing interface instability and crystal cracking. The study also investigated the influence of growth parameters, such as growth rate and crystal rotation rate, on CSC. It was determined that convection plays an important role, and a critical growth condition was identified: when the normalized growth velocity surpasses a certain threshold, the solidification behavior changes, resulting in CSC. In the end, the article compared analytical results with experimental data, demonstrating good agreement between the two.