Study on cracking and low-angle grain boundary defects in YAlO₃ crystal

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• 作者：Li ; Hongjun ; Zhao ; Guangjun ; Zeng ; Xionghui ; Zhou ; Guoqing ; Qian ; Zhenying ; Zhou ; Shengming ; et. al.
• 关键词：Yttrium orthoaluminate crystal ; Defect ; Low-angle grain boundary ; Cracking
• 刊名：Materials Letters
• 出版年：2004
• 出版时间：October, 2004
• 年：2004
• 卷：58
• 期：26
• 页码：3253-3256
• 全文大小：223 K

文摘

Dislocation low-angle grain boundary (mosaic structure) and cracking in yttrium orthoaluminate (YAlO₃) crystal grown by the Czochralski method were studied using scanning electron microscopy (SEM), X-ray, etching, and optical techniques. From dislocation etch pits, the boundary angle of mosaic structure on the (010) plane was estimated to be 56.5??. The rocking curves of four-crystal high-resolution X-ray diffraction (XRD) show that the boundary angle on the plane normal to (010) is 58??. Thermal expansion behavior of Ce:YAlO₃ was studied along several main crystallographic axes between 20 and 800 ??C, and the result shows that there is a large difference in expansion coefficients between [010] and [101??], which is considered to lead the cracking.