| Hydrodynamic effect during crystal growth was observed in a real-time method and the result of experiment was deeply studied in the article which was supported by the national key scientific research projects "Crystal Quality was Affected by Hydrodynamic Effect ".In the article a optical system was developed by the newest RC microscope with the schlieren method, which made the figure of appearance excellent colour and lustre and fine third dimension. The special cylindrical and cubic crystal growth cell was designed and the temperature-control system was developed to cooperate with the cell. Radial thermal gradient was formed in the cylindrical cell while transverse thermal gradient in the cubic cell, which was prepared for finding new effects.Different crystal-growth processes were described quantitatively by in-situ memory of solidification of melt, typical characters of natural convection and instable forced convection were observed qualitatively. The surface tension convection and gravitational convection were observed and distinguished recur to the method of putting microcrystal into the solution. The velocity field of them was studied by theoretical method. Somboonsuk and Trivedo's theory about relativity between Peclet and C-D conversion was supported powerful by the result, and it was concluded that Peclet will be minimum and C-D conversion will happen while GLD/C0m(1 - k0)V = 0.5 .The effect of convection acting on the interface of SCN was studied in the cylindrical crystal growth cell. The solute concentration near the interface in two areas were measured. The analysis of convection in the cell indicated that convection made the solute concentration near crystal well-proportioned,which was suitable to achieve high-quality crystal... |
PDF Full Text Request