二次核化和 ZnO 的生长
Thomas L Sounart1, Jun Liu, James A Voigt
1Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185, USA. thomas.l.sounart@intel.com
Journal of the American Chemical Society
|November 30, 2007
概括
研究人员发现了一种连续晶体生长的新方法,使复杂的等级晶体逐步组装. 该技术使用二胺添加剂控制二次核化,提供可调节的晶体大小和形态.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 化学工程是化学工程的重要组成部分.
背景情况:
- 结晶材料通常根据表面能量在偏好的方向上变大.
- 在现有的晶体平面上观察到一种新奇的二次晶体生长 (分支) 的现象.
- 了解这种二次核化的机制对于控制的晶体组装至关重要.
研究的目的:
- 系统地研究影响二次氧化 (ZnO) 晶体生长的因素.
- 用有机胺添加剂确定二次核化的临界度极限和动力学.
- 阐明二次生长期间可调节晶体大小和形态背后的机制.
主要方法:
- 作为添加剂,有机胺链长度和度的系统变化.
- 测量ZnO分支的临界下部和上部核化度极限.
- 诱导时间和生长速度的动态测量.
- 对ZnO分支的形态分析,以了解生长机制.
主要成果:
- ZnO分支在一个狭窄的二胺度范围内形成,由关键的下限和上限定义.
- 临界核化度随着胺链长度的增加而显著增加.
- 诱导时间和生长速度与二胺度相关,符合经典核化理论.
- 晶体的溶解度,表面蚀刻和超和决定了二次生长的狭窄窗口.
结论:
- 一种连续的核和生长技术允许逐步组装复杂的等级晶体.
- 有机胺添加剂通过影响核化度和动力学来控制二次ZnO晶体的生长.
- 这项研究揭示了可调节晶体大小和形态的基本机制,推进了晶体工程策略.
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