鐵薄膜與鉑基底間溫度相依的介面擴散行為

Abstract

我們利用歐傑電子能譜術配合離子濺射，觀察隨離子濺射打掉表面原子系統表面的組成變化，分析1ML Fe/Pt(111)系統經升溫熱退火後鐵原子的擴散情形，並搭配理論估算鐵在合金各層的分布比例。 觀察570K，700K，910K熱退火後的鐵原子擴散，經由歐傑縱深分析後發現鐵原子大部份分布在表面前兩層至第三層，其中700K與910K鐵原子與白金在表層混合均勻，同時配合理論估算得知700K熱退火後，鐵原子在第一層佔73%，在第二層佔23%；910K熱退火後鐵原子在第一層佔 70%，第二層佔21%，比例差異不大。 1017K下的鐵原子則已經鑽入內層與白金均勻混合成類似塊材合金的結構。以理論估算得知鐵原子在每一層比例佔11%至15%，表示鐵原子往內層擴散並與白金混合均勻。

The composition depth profiles of 1ML Fe film on Pt(111) substrate annealing to 570K, 700K, 910K,and 1017K were analyzed by Auger electron spectroscopy(AES). After annealing 1ML Fe film on Pt(111) substrate, the surface was sputtered and detected by AES sequentially until iron was not observed. The proportions of iron at different layers were determined through the formula of depth profiles. After annealing to 570K, 700K, and 910K, less iron atoms could diffuse to the third layer. Meanwhile, after annealing to 700K, the percentages of iron atoms are 73% and 23% at first and second layer, respectively. The percentages of iron atoms after annealing to 910K are 70% and 21% at first and second layer, respectively. It shows the percentages of Fe atoms are stable at annealing temperature 770K and 910K. It manifests that the percentages of Fe atoms are not only related to the annealing temperature but also affected by the stability of Fe-Pt alloys. As annealing to 1017K, iron atoms could diffuse to deeper than the third layer because of the broken of the stability of Fe-Pt alloys. Furthermore, the percentages of iron atoms at each layer above the fourth layer range between 11% and 15%. It presumes that Fe-Pt alloy iron atoms were well-mixed vertically at each layer.