کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5424926 | 1395842 | 2007 | 7 صفحه PDF | دانلود رایگان |
The size distribution and shape transition of self-assembled vanadium silicide clusters on Si(1Â 1Â 1) 7Â ÃÂ 7 have been investigated by scanning tunneling microscopy. Nanoclusters were formed by submonolayer vanadium deposition at room temperature followed by subsequent annealing (solid phase epitaxy - SPE). At room temperature, initially V-nanoclusters are formed which occupy sites avoiding the corner hole parts of the unit cells in the Si(1Â 1Â 1) 7Â ÃÂ 7 surface. Upon annealing, strong metal-silicon reaction occur leading to the formation of vanadium silicide nanoclusters. As a function of temperature, both, flat (2D) and three dimensional (3D) clusters have been obtained. After annealing at temperatures around 900Â K many faceted clusters are created, whereas at higher annealing temperature, around 1300Â K, predominantly 3D clusters are formed. The size distribution of SPE grown clusters could be well controlled in the range of 3-10Â nm. The cluster size depends on the annealing temperature as well as on the initial vanadium coverage. Based on high resolution STM images a structure model for one kind of vanadium disilicide clusters exposing atomically flat surfaces was proposed.
Journal: Surface Science - Volume 601, Issue 21, 1 November 2007, Pages 4881-4887