Semiconducting (Ba,Sr)TiO3 ceramics were solidified using an aerodynamic levitator and the solidification behaviors during recalescence and microstructure of the levitated (Ba,Sr)TiO3 ceramic were investigated. A spheroid (Ba,Sr)TiO3 was synthesized from a homogeneous melt using an aerodynamic levitator. The recalescence was observed, indicating that the undercooled melt solidified into a polycrystalline (Ba,Sr)TiO3 phase. The levitated sample exhibited a radial dendrite structure originating from a surface nucleation point. Secondary dendrites on primary dendrites were formed due to temperature variations at the solid-liquid interface. The as-levitated sample was oxygen-deficient compared to the sintered sample. The aslevitated (Ba,Sr)TiO3 sample had a cubic structure, and the positive temperature coefficient of resistivity (PTCR) characteristics were not observed. To analyze the transformation kinetics during recalescence, the growth velocity of the solid phase was estimated from the snap shot images of the molten droplet during recalescence.

Keywords: Aerodynamic levitation, (Ba,Sr)TiO3 ceramics, Recalescence, Solidification.