引晶直径对泡生法蓝宝石晶体位错及小角度晶界影响的研究

Study on Effect of Necking Diameter on Dislocation and Low-angle Grain Boundary of Sapphire Crystal Grown by Kyropoulos Method

利用晶体生长模拟软件CGSim,模拟了引晶过程中晶体的直径对晶体生长初期晶体的热流密度和轴、径向温度梯度的影响。结果表明:随着引晶直径的减小,晶体肩部的热流密度减小,轴向及径向温度梯度减小,因而能有效的减小晶体内的热应力,减少晶体位错及小角度晶界缺陷,提高晶体质量,模拟结果得到了实验的验证。

In this article, the effect of different necking diameter on thermal field of sapphire crystal were simulated by CGSim software. The results indicate that the heat flux density decreased as the simulated and analyzed necking diameter decreasing, so were the axial and radial temperature gradients of crystal at the necking-shouldering stage. All of these can decrease the thermal stress, dislocation and low-angle grain boundaries and improved the quality of the crystal effectively. The actual products validated the simulation results of our experiments.