臺灣博碩士論文加值系統

利用在Si(111)-Pb表面成長的鉛量子島的模板，二維的奈米銀團簇可以自組織機制成功的形成。奈米銀團簇不但以平面方式成形,更發展可區別的大小及形狀。這些具有強化穩定性的奈米銀團簇被命名為”奇異奈米銀結構”。在目前的工作裡，我們藉由掃描穿隧顯微鏡探討奈米銀結構的熱穩定性，其熱穩定性將以緩慢升溫的模式有系統地被驗證。再者，”奇異奈米銀結構”彼此間的相對穩定性也將被檢驗。此外，奈米銀結構的鄰近效應對其穩定性的影響也是我們感興趣的主題，為了明瞭周圍環境的效應，我們選擇兩種不同鍍量的銀鍍在鉛量子島上，

Utilizing the pattern found on the Pb quantum islands formed above Si(111)–Pb surfaces, two-dimensional Ag nanoclusters can be successfully grown via the self-organized mechanism. Not only are Ag nanoclusters in the planar formed, but also naturally develop into distinct sizes and shapes. Those nanoclusters with enhanced stability are named magic Ag nanopucks. In the present work, scanning tunneling microscopy (STM) is employed to study the thermal stability strength of Ag nanopucks. By slowly raising the sample temperature, the physical stability is systematically demonstrated. Furthermore, the relative stability of magic Ag nanoclusters is also examined. In addition, the surrounding effect on the stability is also of our interest in the present work. For the purpose of realizing this effect, two different deposition coverage were chosen to deposit onto Pb quantum islands.

Table of Contents

Abstract
Acknowledgements
Table of Contents
List of Figures
Chapter 1. Introduction--------------------------------1

Chapter 2. Principle of scanning tunneling microscopy--5
2.1 Tunneling theory-----------------------------------6
2.2 Local density of states--------------------------- 7
2.3 STM operating modes-------------------------------10
2.3.1 Constant current modes--------------------------12
2.3.2 Constant height modes---------------------------13
2.3.3 Current image tunneling spectroscopy (CITS)-----15

Chapter 3. Experimental details-----------------------17
3.1 Experimental systems------------------------------17
3.1.1 UHV system--------------------------------------19
3.1.2 STM system--------------------------------------23
3.1.3 Evaporator system-------------------------------27
3.1.4 Vibration isolation-----------------------------29
3.2 Tip preparation-----------------------------------31
3.3 Sample preparation--------------------------------32


Chapter4. The thermal stability of the 2D Ag
nanoclusters on Pb quantum islands----------34
4.1 Motivation----------------------------------------34
4.2 Experimental procedures---------------------------37
4.3 Results and discussions---------------------------40
4.3.1 Temperature dependence of magic Ag nanopucks on
the thermal stability---------------------------40
4.3.2 Surrounding effect on the thermal stability of
2D Ag nanopucks---------------------------------48
4.4 Conclusion----------------------------------------53

References

Reference

[1]M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science
262 , 218 (1933).
[2]S. J. Tans, M. H. Devoret, H. Dai, A. Thess, R. E.
Smalley, T. J. Geerligs, and C. Dekkar, Nature 386, 474
(1997).
[3]E. Scheer, N. Agrait, J. C. Cuevas, A. L. Yeyati, B.
Ludoph, A. Martin-Rodero, G. R. Bollinger, J. M. V.
Ruitenbeek and C. Urbina, Nature 394, 154 (1998).
[4]L. L. Sohn, Nature 394, 131 (1998).
[5]W. A. de Heer, Rev. Mod. Phys. 65, 611 (1993).
[6]W. D. Knight et al., Phys. Rev. Lett. 52, 2141 (1984).
[7]T. P. Martin, T. Bergmann, H. Gohlich, and T. Lange,
Chem. Phys. Lett. 172, 209 (1990).
[8]O. Echt, K. Sattler, and E. Recknagel, Phys. Rev. Lett.
47, 1121 (1981)
[9]W. Miehle, D. Kandle, T. Leisner, and O. Echt, J. Chem.
Phys. 91. 5940 (1989).
[10]H.-P. Cheng and U. Landman, Science 260, 1304 (1993),
and references therein.
[11]Roland Wiesendanger, Scanning Probe Microscopy,
Springer, New York, (1998).
[12]G. Binning, H. Rohrer, C. Gerber, and E. Weibel, Phys.
Rev. Lett. 49, 57 (1982).
[13]R. M. Feenstra and A. J. Slavin, Surf. Sci. 251/252,
401 (1991).
[14]真空技術與應用, 行政院國家科學委員會精密儀器發展中心.
[15]W. B. Jian, W. B. Su, C. S. Chang, and Tein. T. Tsong,
Phys. Rev. Lett. 90, 196603 (2003).
[16]S. M. Lu, H. T. Shih, C. L. Jiang, W. B. Su, C. S.
Chang, and Tien T. Tsong. Phys. Rev. B 75, 113402
(2007)
[17]M. Hupalo, V. Yeh, T. L. Chan, C. Z. Wang, K. M. Ho,
and M. C. Tringides, Phys. Rev. B 71, 193408 (2005).
[18]T. L. Chan, C. Z. Wang, M. Hupalo, M. C. Tringides, W.
C. Lu, K. M. Ho, Surf. Sci. 600, L179 (2006).
[19]H.Y. Lin, Y. P. Chiu, L.W. Huang, Y.W. Chen, T.Y. Fu,
C. S. Chang, and Tien T. Tsong, Phys. Rev. Lett. 94,
136101 (2005).
[20]Ya-Ping Chiu, Li-Wei Huang, Ching-Ming Wei, Chia-Seng
Chang, and Tien-Tzou Tsong, Phys. Rev. Lett. 97,
165504 (2006).
[21]國立台灣師範大學物理研究所博士論文”奈米銀結構在鉛量子
島上之自我有序成長與電性結構” 邱雅萍 撰 (2005)
[22]國立中央大學化學工程與材料工程研究所博士論文”低溫成長
有序排列銀及鉛奈米結構於鉛量子島上及單層鉛薄膜之相變
化” 林欣瑜 撰 (2004)