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 Bi SbTe3 -mixed crystals at normal and at reduced gravity. The growth experime nts in space, including a dynamical registration of the temperature distrib ution of the furnace, were performed during the MIR'97 :mission. The transi ent temperature profiles have been analysed to get thermal boundary conditi ons for numerical simulations of convection and segregation with the FEM pa ckage 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 th e resulting Buoyancy driven flow configuration in the melt and its influenc e on the radial and axial segregation depending on the gravity level.