鋪覆超薄膜於針狀金屬表面之現象研究

Abstract

本實驗藉由場離子顯微鏡，觀察超薄膜鋪覆於針狀金屬表面之現象。其實驗現象可分為兩方向討論，其一為覆鉑於鈷針狀結構，由於切面擴張產生皺化現象。加熱退火至600K，可發現由於鉑之鋪覆，增加表面能異向性、降低皺化所需之加熱退火溫度，使得表面自由能較低的(0001)、(1013)、 (1013)切面擴張，並形成單條稜線，但由於鈷為非耐火性之材料，因此易受加熱退火影響，使得稜線成長不完整，難以觀察到金字塔堆疊。 另一方向為，覆矽於銥及鉑針狀結構，成長單層皺形之蜂巢結構-Silicene。由於場離子顯微鏡可看到同一樣品之各個切面，因此可觀察矽於各個切面成長之穩定結構：覆矽於銥(111)切面可發現，同時蒸鍍及加熱退火，可成長較特殊的結構；於銥(100)切面可觀察到矽原子排列成(3×2)之結構；於(311)、(310)及台階邊緣可成長帶狀、六角結構。 覆矽於鉑(111)切面，可觀察切面上可成長六角結構，與現在備受討論的議題-「Silicene」具有相似結構，因此推測鉑也可能成為成長Silicene之基底。

The study is about the phenomena of ultrathin film covered metal tip surfaces by field ion microscope. It can be divided into two directions. One is for faceting phenomena of platinum covered cobalt tip which will increase the surface energy anisotropy, lower the temperature of faceting let (0001) and {1013} faces expanding resulted in the formation of crest lines at 600K. But due to cobalt is a nonrefractory material the crest lines are not complete. The other one, silicon covered iridium and platinum tip growth buckled honeycomb structure. With the field ion microscope, we can see the various facets of the same sample, so we can observe the stable structure of each section: at Ir(111) facet we can found more special structures; at Ir(100) facet we can observe the silicon atoms be arranged in (3×2) structure; at (311), (310) and the platform edge, strip and hexagonal structure can be grown. The facets of silicon covered platinum (111), the surface can develop into hexagonal structures, with the extensive discussed issue of "Silicene" has a similar structure, therefore ,it could infer that platinum may also become a growing substrate of Silicene .