Growth of BiSbTe3-mixed crystals using a Bridgman configuration of the TITUS furnace -: Numerical simulation of convection and segregation

A standard Bridgman configuration of the TITUS facility was used to grow BiSbTe3 -mixed crystals at normal and at reduced gravity. The growth experiments in space, including a dynamical registration of the temperature distribution of the furnace, were performed during the MIR'97 :mission. The transient temperature profiles have been analysed to get thermal boundary conditions for numerical simulations of convection and segregation with the FEM package FIDAP. The calculations have been done within the frame of a 3D model close to the real growth conditions. The aim of the paper is to discuss the resulting Buoyancy driven flow configuration in the melt and its influence on the radial and axial segregation depending on the gravity level.