【摘要】 流体效应是影响晶体生长传热、传质过程和晶体完整性的主要因素 ,了解其机理将有利于生长优质晶体。我们在空间晶体生长实时观察装置上 ,利用2 0 μm的碳酸钠作示踪粒子 ,首次在高温氧化物熔液内同时观察到了表面张力和重力对流效应 ,并利用测量的结果计算了熔液内表面张力对流和重力对流的速度场。实验结果表明 :近坩埚壁处 ,主要以表面张力对流起主导作用 ,而在熔液区域内 ,重力对流效应显著。更多还原

【Abstract】 Fluid flow effects play an important role in the processes of heat transport,mass transport and growing interface kinetics in crystal growth.Hence,a good understanding of its mechanism is beneficial to growing high-quality crystal.Because of the uneven temperature distribution of the loop resulting from the electric thermo-couples,the surface tension convection and the gravitational convection,for the first time,were simultaneously observed in high temperature oxide solution by using the space high temperature situ observation facility and the traced particles of 20μm Na 2CO 3 in the diameter.The velocity field of the surface tension convection and the gravitational convection were theoretically calculated through the detected experimental data in the solution,meantime,the related fluid dynamic equations are performed to certify theoretically our experimental results.The surface tension convection plays a main role near to margin of the loop and the gravitational convection effect is rather sharp within the solution.更多还原