Translated Titles

STM Study of Pulse Induced CO Dissociation



Key Words

掃描穿隧顯微儀 ; 解離 ; 電壓脈衝 ; 一氧化碳 ; 矽 ; STM ; dissociation ; pulse ; CO ; Silicon



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Chinese Abstract

本文主要是利用掃描穿隧顯微儀電壓脈衝誘發CO產生解離的研究。文中首先統計出CO低溫少量吸附在矽(111)-7×7樣品表面上時,較易吸附在『faulted half unit cell』的『corner』位置上。而且,當改變樣品偏壓時,CO的影像均為亮點。 接著在吸附的CO上施以電壓脈衝,藉此探討電壓脈衝是否可能誘發CO產生解離現象,並歸納其條件,此亦為本文重點。 最後,實驗所得,當(樣品偏壓,電壓脈衝)(sample bias,biasd voltage)的值為:(-1.8V,-2.2V)、(-1.2V,-3.0V)、(-1.0V,-2.4V)、(-1.0V,-2.0V)、(-1.0V,-1.2V)、(-1.0V,-1.0V)時,我們較易觀測到一氧化碳分子因為此電壓脈衝而發生幾何結構上的變化;然後,我們繼續施加電壓脈衝,當此電壓脈衝恰巧打中碳原子與氧原子之間的鍵結時,才有可能切斷其間之鍵結,進而誘發『解離』現象發生。在誘發解離成功的影像中,我們觀察到在原來一氧化碳的吸附位置上,會出現一個黑點,而在旁邊的原子上則有一個亮點產生。

English Abstract

This thesis is a STM study of pulse-induced dissociation of CO. First, we compile the statistics and conclude that when a small amount of CO is adsorbed on the Si(111)-7×7surfaces at 80K, it tends to be adsorbed in the corners of the faulted half unit cell of the Si(111)-7×7 surfaces. Besides, as the sample bias is changed, all the STM images of CO appear to be bright spots. Second, we apply pulses on the adsorbed CO; thereby we explore if pulses can induce CO to be dissociated and we generalize the conditions required. This is also what the thesis focuses on. Finally, we discover that when the values of sample bias and the relative pulse applied are(-1.8V,-2.2V)、(-1.2V,-3.0V)、(-1.0V,-2.4V)、(-1.0V,-2.0V)、(-1.0V,-1.2V)、(-1.0V,-1.0V), changes of the CO molecule in geometric structure take place. Then, we continue to apply the pulse, and find that only when the pulse hits right on the bond of C and O, it is able to cut the bond and induce dissociation. In the image of successfully pulse-induced dissociation, we observe that on the original location of the adsorbed CO occurs a dark spot, and a bright spot occurs on the nearby atom.

Topic Category 基礎與應用科學 > 物理
理學院 > 物理學系
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Times Cited
  1. 鄭晃翔(2008)。矽(111)表面上矽奇異原子團的掃描穿隧能譜與分析。臺灣大學物理研究所學位論文。2008。1-63。