本實驗利用場離子顯微鏡觀察吸附矽原子在銥(100)切面上的動態行為及交互作用。利用單顆吸附矽原子在不同溫度下的熱擴散運動，並配合Arrhenius plot求得擴散活化能E_d=0.91±0.02 eV。雙顆吸附矽原子在加熱到400 K以上時，彼此間的距離較低溫時的大，也間接證明在此溫度下，原子有足夠的能量去排列成有序結構。觀察雙顆吸附矽原子在銥(100)切面上的動態分布，顯示出矽原子在銥(100)切面上會位於不同佔位上(例如：四重對稱站位、橋位和上位)，也表示矽原子彼此間的交互作用力大於矽原子與基底間的交互作用。雙顆吸附矽原子會在相距三個銥基底的晶格常數下處在最低的交互作用能0.086 eV。原子間的交互作用會受到基底的二維自由電子氣影響，產生Fridel oscillation的現象，藉由理論公式與實驗數據擬合，可以得到銥(100)切面上的費米波向量應該為1.35 Å。當加熱到431 K時，蒸鍍在銥(100)切面下的矽原子會發生上行運動。

This study is about the dynamics and interaction of silicon adatoms on Ir(100) by field ion microscopy (FIM). The activation energy of a single silicon adatom diffusion on Ir(100) which is calculated with the diffusion motion at different temperature and the Arrhenius plot is 0.91±0.02 eV. The distance of the two silicon adatoms heated above 400 K is larger than at low temperature. That is the silicon atoms would have enough energy to arrange the order structure at 400 K. The distribution of two silicon adatoms on Ir(100) shows the silicon adatoms on the different sites (ex. 4-fold site, bridge site and top site). That is the interaction energy between the two silicon adatoms is larger than the interaction energy between silicon adatom and iridium. The lowest interaction energy of two silicon adatoms is -0.086 eV as they are between 3 iridium lattice constants. 2-dimetion free electron gas of iridium surface results in Fridel oscillation. We calculated the Fermi wave vector of Ir(100) surface was 1.35 Å by fitting formula. The silicon adatoms on Ir(100) would be step up motion above 431K.

[1] K.S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, A.A. Firsov, Electric field effect in atomically thin carbon films, Science, 306 (2004) 666.
[2] B. Lalmi, H. Oughaddou, H. Enriquez, A. Kara, S. Vizzini, B. Ealet, B. Aufray, Epitaxial growth of a silicene sheet, Applied Physics Letters, 97 (2010) 223109.
[3] B. Feng, Z. Ding, S. Meng, Y. Yao, X. He, P. Cheng, L. Chen, K. Wu, Evidence of Silicene in Honeycomb Structures of Silicon on Ag(111), Nano Letters, 12 (2012) 3507-3511.
[4] L. Meng, Y. Wang, L. Zhang, S. Du, R. Wu, L. Li, Y. Zhang, G. Li, H. Zhou, W.A. Hofer, H.-J. Gao, Buckled Silicene Formation on Ir(111), Nano Letters, 13 (2013) 685-690.
[5] W. Wei, Y. Dai, B. Huang, M.-H. Whangbo, T. Jacob, Loss of Linear Band Dispersion and Trigonal Structure in Silicene on Ir(111), The Journal of Physical Chemistry Letters, 6 (2015) 1065-1070.
[6] D. Kaltsas, L. Tsetseris, A. Dimoulas, Silicene on metal substrates: A first-principles study on the emergence of a hierarchy of honeycomb structures, Applied Surface Science, 291 (2014) 93-97.
[7] 陳晏清, 鋪覆超薄膜於針狀金屬表面之現象研究, 國立台灣師範大學碩士論文, (2013).
[8] K.A. Fichthorn, M.L. Merrick, M. Scheffler, Nanostructures at surfaces from substrate-mediated interactions, Physical Review B, 68 (2003) 041404.
[9] T.T. Tsong, Mechanisms of surface diffusion, Progress in Surface Science, 67 (2001) 235-248.
[10] T.-Y. Fu, T.T. Tsong, Structure and diffusion of small Ir and Rh clusters on Ir(001) surfaces, Surface Science, 421 (1999) 157-166.
[11] C. Chen, T.T. Tsong, Displacement distribution and atomic jump direction in diffusion of Ir atoms on the Ir(001) surface, Physical Review Letters, 64 (1990) 3147-3150.
[12] G.L. Kellogg, P.J. Feibelman, Surface self-diffusion on Pt(001) by an atomic exchange mechanism, Physical Review Letters, 64 (1990) 3143-3146.
[13] T.T. Tsong, C.-L. Chen, Atomic replacement and vacancy formation and annihilation on iridium surfaces, Nature, 355 (1992) 328-331.
[14] T.T. Tsong, Atom-Probe Field Ion Microscopy: Field Ion Emission, and Surfaces and Interfaces at Atomic Resolution, Cambridge University Press, 1990.
[15] E.W. Müller, T.T. Tsong, Field Ion Microscopy Principles and Applications, American Elsevier Publishing Company, 1969.
[16] 高玉娟, 鉑或銥原子團在鉑表面之擴散研究, 國立台灣師範大學碩士論文, (1998).
[17] A. Łukaszewski, A. Szczepkowicz, Computer simulation of FIM images – the convex hull model, Vacuum, 54 (1999) 67-71.
[18] 行政院國家科學委員會, 真空技術與應用, 精密儀器發展中心, (2001).
[19] 陳怡如, 覆鈀、銥於鉬針形成金字塔單原子針尖之研究, 國立台灣師範大學碩士論文, (2011).
[20] 丁南宏, 方宏聲, 方振洲, 牛. 寰, 等51人, 真空技術與應用, 國科會精密儀器發展中心, (2001).
[21] 王晨育, 矽於鎢表面的擴散與成長, 國立臺灣師範大學碩士論文, (2015).
[22] 黃意茹, 以場離子顯微鏡研究鎢表面上鈀吸附原子間的交互作用, 國立台灣師範大學碩士論文, (2002).
[23] G. Ehrlich, F. Watanabe, Atomic interactions on crystals: a review of quantitative experiments, Langmuir, 7 (1991) 2555-2563.
[24] S.J. Koh, G. Ehrlich, Pair- and many-atom interactions in the cohesion of surface clusters: Pdx and Irx on W(110), Physical Review B, 60 (1999) 5981-5990.
[25] 傅祖怡, 以場離子顯微鏡對銥表面原子動態的研究, 國立台灣師範大學博士論文, (1997).
[26] C.-l. Chen, T.T. Tsong, Behavior of Ir atoms and clusters on Ir surfaces, Physical Review B, 41 (1990) 12403-12412.
[27] S. Petersson, J. Baglin, W. Hammer, F. d’Heurle, T.S. Kuan, I. Ohdomari, J. de Sousa Pires, P. Tove, Formation of iridium silicides from Ir thin films on Si substrates, Journal of Applied Physics, 50 (1979) 3357-3365.
[28] F. Watanabe, G. Ehrlich, Direct mapping of adatom-adatom interactions, Physical Review Letters, 62 (1989) 1146-1149.
[29] T.-Y. Fu, T.Y. Wu, T.T. Tsong, Oscillatory Adatom-Adatom Interactions of 1D and 2D Surface Diffusion Systems, CHINESE JOURNAL OF PHYSICS, 43 (2005) 1-II.
[30] O. Krogh Andersen, A.R. Mackintosh, Fermi surfaces and effective masses in F.C.C. transition metals, Solid State Communications, 6 (1968) 285-290.