MAGNETOHYDRODYNAMIC DAMPING OF CONVECTION DURING VERTICAL BRIDGMAN-STOCKBARGER GROWTH OF HGCDTE

In order to quantify the effects of convection on segregation, Hg0.8Cd 0.2Te crystals were grown by the vertical Bridgman-Stockbarger method in the presence of an applied axial magnetic field of 50 kG. The influ ence of convection, by magneto-hydrodynamic damping, on mass transfer in the melt and segregation at the solid-liquid interface was investig ated by measuring the axial and radial compositional variations in the grown samples. The reduction of convective mixing in the melt through the application of the magnetic field is found to decrease radial seg regation to the diffusion-limited regime. It was also found that the s uppression of the convective cell near the solid-liquid interface resu lts in an increase in the slope of the diffusion-controlled solute bou ndary layer, which can lead to constitutional supercooling.