1 / 23

r c

第六章 薄膜生长的成核长大热力学. r c. r. Total free energy change ΔG for an embryo of the solid phase, as a function of the embryo radius R, for two values of ΔG v . ( 过饱和度 S 1 >S 2 ). Gibbs-Curie-Wulff 公式:. V+C 两相. Gibbs-Curie-Wulff 公式. 多面体核:. 面心立方晶体的平衡外形为截角八面体,则成核功. 最近邻近似. a. a i. a s. r.

moana
Download Presentation

r c

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 第六章 薄膜生长的成核长大热力学 rc r

  2. Total free energy change ΔG for an embryo of the solid phase, as a function of the embryo radius R, for two values of ΔGv. (过饱和度S1>S2)

  3. Gibbs-Curie-Wulff公式: V+C两相

  4. Gibbs-Curie-Wulff公式

  5. 多面体核: 面心立方晶体的平衡外形为截角八面体,则成核功 最近邻近似

  6. a ai as r

  7. 温度和沉积速率的影响: 一般情况下 讨论:T,R 

  8. 温度和沉积速率对微结构的影响:Cu/NaCl(111)

  9. 衬底缺陷上成核:增原子与缺陷的结合能常常大于增原子和完整表面的结合能,因此晶核会首先在缺陷处形成。衬底缺陷上成核:增原子与缺陷的结合能常常大于增原子和完整表面的结合能,因此晶核会首先在缺陷处形成。 a 多晶衬底的三叉晶界可近似成三角锥 as q ai j 成核功:

  10. m m n 非均匀成核: 简单立方:

  11. 讨论:1、粗略近似下,成核理论的原子模型与热力学模型的结论相仿。讨论:1、粗略近似下,成核理论的原子模型与热力学模型的结论相仿。 2、精确考虑时(量子力学计算),自由能与核尺寸的关系分段,可能有多个最小值(magic number)。 Shangjr Gwo,Phys. Rev. Lett. 90, 185506 (2003)

  12. 薄膜生长的三种模式: 同质外延时的单层核与双层核: 简单立方 直线 共7个AA键 4原子 正方形 共8个AA键 单层 共18个AA键 8原子 双层 共16个AA键

  13. 异质外延时的单层核与双层核: 简单立方

  14. 浸润与键能的关系:

  15. 有三种生长模式

  16. 岛状生长 逐层 +岛状 逐层生长 Frank-van der Merwe Volmer-Weber Stranski-Krastanov 异质外延生长S-K模式最为普遍

  17. 层状生长与岛状生长模式的转变 r 在转变过程中的吉布斯自由能变化: h “Materials science of thin films” P382

  18. Stability regions of the three film growth modes in coordinates of surface energy difference between film and substrate and lattice misfit.

  19. AES谱分析薄膜生长的三种模式

  20. 实例:Metal on TiO2

More Related