氫、氧誘發鎳表面金字塔型單原子針尖

Hydrogen and oxygen induce formation of nickel pyramidal single-atom tips

戴鵬哲(Peng-Che Dai)

指導教授 ： 傅祖怡

國立臺灣師範大學/理學院/物理學系/碩士(2009年)

摘要

本實驗利用氣體誘發與加熱退火的方式成長鐵磁性單原子針。觀察鎳在不同溫度及不同氣體的環境下加熱退火後各切面擴張的現象。當曝氫氣壓~10-7 torr並且600K加熱5 分鐘，觀察到{311}擴大的現象；接著再曝氧~10-7 torr於600K加熱5 分鐘後(110)擴張與{311}共同取代(210)而形成單原子針。
成長的單原子針依照面心立方堆積，則每層原子數為1、6、15…等，而若因成長速度差異造成(110)面缺少一層，就可觀察到每層原子數為1、3、10…的特殊面心立方堆積單原子針。

關鍵字

鎳 ； 金字塔

並列摘要

By means of gas adsorption with annealing, we are trying to fabricateferromagnetic SATs (single-atom-tips) in the experiment. Hydrogen adsorption was introduced at ~10-7 torr with annealing at 600K for 5 min, the surface expansion of {311} is first observed due to high surface energy difference between {210} and {311}. After oxygen adsorption is exposed at ~10-7 torr with annealing at 600K for 5 min, the surface {210} is completely replaced by {311} and {110}, the pyramidal SATs have been generated.
There are two types of SATs that we have observed. In normal FCC pyramidal SATs, the number of atoms are 1, 6, and 15…in series of top layers. And there are 1, 3, and 10…atoms in the top layers of special FCC pyramidal SATs.

參考文獻

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