Thermal stresses produced in single crystals with curved interface grown by laser-heated pedestal growth

Solid-state interactions are simulated by computations. The thermal stress produced during the fiber growth by LHPG induced by temperature variations for various Biot number and interface shape of the melt and the solid. Simulations show that maximum stress and dislocation density are produced during the single crystal growth for the growing interface concaving towards the melt with large Biot number. The temperature distribution distant from the interface has little or no difference no matter it is the convexed and the concaved conditions along the axial and radial direction. However, Concaved-interface single crystals have 4.8 times thermal stress (dislocation) higher than convexed-interface at the periphery of the tip. The thermal stresses or dislocation density of the spinel calculated from the optical micrograph photographs show the same trends as the model derived.