提拉法生长大尺寸γ-LiAlO_2单晶的研究(英文)  

Study on Large-size γ-LiAlO_2 Single Crystal Grown by Czochralski Technique

作　　者：彭观良[1] 邹军[1] 庄漪[1] 张涟翰[1] 周国清[1] 周圣明[1] 徐军[1] 干福熹[1] 

机构地区：[1]中国科学院上海光学精密机械研究所

出　　处：《人工晶体学报》2005年第2期278-282,223,共6页Journal of Synthetic Crystals

摘　　要：由于与GaN晶格失配小(约1. 4% ),γLiAlO2 单晶有望成为一种很有希望的GaN外延衬底材料。本文使用提拉法生长出了尺寸达45×50mm3 的γLiAlO2 单晶。对该晶体毛坯的各个有代表性的位置作了X射线粉末衍射(XRPD)分析,结果表明仅仅在晶体毛坯的底部生成了一种缺锂相(LiAl5O8 )。γLiAlO2 晶体化学稳定性差,在室温时轻微水解。当在空气中于1100℃退火70h,γLiAlO2 晶体挥发出锂组分,在表面产生缺锂相(LiAl5O8 )。值得注意的是,在γLiAlO2 晶体的红外光谱区不存在氢氧根吸收带。γ-LiAlO2 single crystals were anticipated to act as a promising substrate material for the epitaxy of GaN because of the little lattice misfit (about 1.4%) between each other. In the present work, large-size γ-LiAlO2 single crystal with dimension of φ45 × 50 mm3 has been grown by Czochralski technique. Various representative positions of the crystal boule were examined using X-ray powder diffraction (XRPD) analysis. Only in the bottom of the crystal boule there produced a kind of lithium-poor phase (LiAl5O8). The γ-LiAlO2 crystal exhibits a poor chemical stability because it hydrolyzes slightly at room temperature. When the γ-LiAlO2 crystal was annealed for 70 h at 1100°C in air-atmosphere, it volatilizes a lithium component, and produces a lithium-poor phase (LiAl5O8) layer on the surface. It is noteworthy that no hydroxyl absorption band presents in the infrared spectra region of γ-LiAlO2 crystals.

关 键 词：提拉法 晶体 生长工艺 γ-LiAlO2 缺锂相 化学稳定性 

分 类 号：O782.5[理学—晶体学]