热交换法生长蓝宝石晶体的位错研究

Research of Dislocations of Sapphire Crystals Grown by Heat-exchange Method

本文用热交换法生长出a向,尺寸为150 mm×160 mm,重10 kg的低位错蓝宝石晶体,并采用化学腐蚀-金相显微镜法观测了(0001)晶面的位错形貌。结果显示:(0001)晶面的位错腐蚀坑呈三角形,分布较均匀和分散,图像清晰,平均位错密度较低,为2.1×103Pits/cm2;热交换系统保温效果好,能独立控制熔体和晶体的温度梯度,温场起伏小,具有良好的稳定性和可控性,适合用来生长大直径低位错的蓝宝石晶体。

The sapphire crystals containing low dislocations, which 10 kg in weight and φ150 mm×160 mm in size had been successfully grown along a axis by means of heat-exchange method and the dislocations appearance of （0001） plane had been observed with chemistry eroding- metalloscope. The result shows that the shape of etch pits located in （0001） plane as a triangle structure distributs comparatively uniformly and dispersively and low average dislocations density is 2.1×10^3Pits/cm^2. It indicates that heat-exchange system had good heat preservation effect, controlled temperature gradients of crystal and melt independently, little temperature fluctuation, possessed well stability and controllability,adapted to be used to grow sapphire crystals of major diameter and low dislocations.