由接口核化机制驱动的合体In2O3纳米晶体的相位转换:一项动力学研究
Shokouh S Farvid1, Pavle V Radovanovic
1Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Journal of the American Chemical Society
|March 28, 2012
概括
合体氧化物纳米晶体通过接口核化从转移稳定转变为稳定阶段. 较小的纳米晶体由于接触概率增加而转化得更快,从而可以控制结构.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 固态化学 固态化学
背景情况:
- 合体氧化物纳米晶体 (In(2) O(3) NCs) 可以存在于不同的晶体相.
- 了解相变动动力学对于控制NC属性至关重要.
研究的目的:
- 在合成过程中研究In(2) O(3) NC的相变动力学.
- 阐明相变的机制和影响因素.
主要方法:
- 在X射线衍射 (XRD) 中.
- 传输电子显微镜 (TEM) 的使用
- 扩展的X射线吸收细结构 (EXAFS) 光谱学.
- 约翰逊-梅尔-阿弗拉米-埃罗费耶夫-霍尔莫戈罗夫 (JMAEK) 和接口核化模型.
主要成果:
- 在 (((2) O ((3)) 中,NCs最初在转移稳定的冠状体 (rh) 阶段稳定,然后转化为立方比克斯比特 (bcc) 阶段.
- 阶段转换发生在接触的NC之间通过接口核化.
- 转换的激活能量为152 ± 60kJ/mol;较小的NC由于包装密度较高,转换速度更快.
结论:
- 接口核化是In(2) O(3) NC相变的主要机制.
- NC大小,包装密度和接触概率显著影响转换动力学.
- 控制合成条件和反应动力学允许操纵NC结构和属性.
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