Spiral formation during Czochralski growth of rare-earth scandates

Single crystals of the rare-earth scandates DyScO3, GdScO3, SmScO3, and NdScO3 were grown by the Czochralski technique. The influence of the absorption of radiant heat in the growing crystals on interface stability was investigated. Numerical simulations were performed to calculate the influence of thermal instabilities close to the growth interface on the axial symmetry of the flow field, which eventually leads to spiral growth. To inhibit spiral formation, a conical baffle was utilized to intensifying the buoyant-thermocapillary convection.