Double diffusive convection during growth of lead bromide crystals

We have carried out detailed experiments on the growth of pure and doped lead bromide (PbBr 2) crystals in 1-g conditions to evaluate the effect of thermo-solutal convection on the crystal homogeneity. The thermal and solutal Rayleigh numbers were changed by altering the aspect ratio of the growth ampoule and the concentration of the silver bromide impurity in the lead bromide. A preliminary numerical analysis was also carried out which provided the boundary conditions for the minimum needed during the diffusion controlled growth of lead bromide crystals.