·202· 北京科技大学学报 2002年第2期 图4T-Zn0晶须的形貌(1050℃)(a)氧分压一定，b)增大氧分压 Fig.4 SEM micrographs of T-ZnO whiskers(1050C) 氧气的分压.反应器内的氧分压易于调控；而 度，可以获得高纯、尺度可控（针长为5~30m, Zn蒸气的分压除了与反应器体积有关外，温度 针体根部约1~2m,尾部为100nm)、结晶完整 的高低更直接影响到反应器中Zn蒸气的浓度. 的高品质T-Zn0晶须，产率可达95%.晶须的 实验结果表明，在温度低于780℃时，无Zn0晶 生长机理为气-固生长机理(VS). 须形成，要生成晶须必须使温度高于780℃.其 参考文献 他条件（如反应器体积、氧气分压等）相同时，温 1 Hu J,Ma X,Xie Z,et al.Characterization of Zinc Oxide 度越高，蒸气压越大.图4(a)为1050℃时制备的 Crystal Whiskers Grown by Thermal Evaporation [J]. T-Zn0晶须，针长约为20-30m,根部尺寸约为 Chem Phys Lett,2001,344(1-2):97 2m.该晶须的尺度比950℃时（见图2）制备的 2 Satoh,Tanaka N,Ueda Y,et al.Homogeneous Growth of T-ZnO晶须大，表明晶须的尺度随温度的升高 Zinc Oxide Whiskers[J].Jpn J Appl Phys,1999,38(12A): 而增大.图4b)为1050℃下增大氧分压时制备 6873 的T-ZnO晶须，图中的晶须发育程度不良，生 3 Yoshinaka M,Asakuya E,Yagi J,et al.Method of Produc- ing Zinc Oxide Whiskers[P].EP,378995.1990-07-25 长不均匀，针间有大量片状物出现，晶须品质 4李树尘.碳还原剂控制氧化锌晶须生产工艺方法P] 差.因此，要得到结晶规整的T-ZnO晶须，需严 中国专利，1101952A.1995-4-26 格控制反应体系内的反应气相的过饱和度. 5陈尔凡，田雅娟，程远杰，等.四角状氧化锌晶须的制 备及微观形态研究[】.高等学校化学学报，2000,21 3结论 (2):172 采用锌粉氧化的方法制备出T-ZnO晶须， 6 Kitano M,Hamabe T,Maeda S,et al.Growth of Large Tet- rapod-like ZnO Crystals(I)Experimental Considerations 反应器内的气相过饱和度是晶须生长的关键因 on Kinetics of Growth[J].J Cryst Growth,1990,102 (4): 素.通过适当控制反应器内的反应气相过饱和 965 Structure and Growth Mechanism of High-quality Tetrapod-like ZnO Whiskers DAI Ying,ZHANG Yue Department of Materials Physics,UST Beijing,Beijing,100083,China ABSTRACT The tetrapod-like ZnO whiskers were synthesized by oxidation of the Zn powders.High purity and perfect crystalline T-ZnO whiskers with different sizes were obtained by controlling gas supersaturation in the reaction container.The length of legs of the whiskers is approximately 5-30 um and the geometrical edge size of centering nucleus is approximately 1-2 um.Especially,the whiskers had long tail about 100nm. The whiskers grew via Vapor-Solid mechanism.Gas supersaturation in the reaction container is the key to pre- pare high-quality T-ZnO whiskers