کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5423420 1507933 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tantalum induced butterfly-like clusters on Si (111)-7 Ã— 7 surface: STM/STS study at low coverage
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Tantalum induced butterfly-like clusters on Si (111)-7 Ã— 7 surface: STM/STS study at low coverage
چکیده انگلیسی

The adsorption of the small amounts of tantalum on Si (111)-7 × 7 reconstructed surface is investigated systematically using scanning tunneling microscopy and tunneling spectroscopy combined with first-principles density functional theory calculations. We find out that the moderate annealing of the Ta covered surface results in the formation of clusters of the butterfly-like shape. The clusters are sporadically distributed over the surface and their density is metal coverage dependent. Filled and empty state STM images of the clusters differ strongly suggesting the existence of covalent bonds within the cluster. Tunneling spectroscopy measurements reveal small energy gap, showing semiconductor-like behavior of the constituent atoms. The cluster model based on experimental images and theoretical calculations has been proposed and discussed. Presented results show that Ta joins the family of adsorbates, that are known to form magic clusters on Si (111)-7 × 7, but its magic cluster has the structural and electronic properties that are different from those reported before.

► Annealing of Ta covered Si (111)-7 × 7 surface forms clusters of butterfly-like shape. ► Filled and empty state STM images of the clusters appear differently. ► STS reveals small energy gap, showing semiconducting behavior of constituent atoms. ► A cluster model was proposed comprising 5 tantalum atoms placed in hollow sites (H3).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 606, Issues 3–4, February 2012, Pages 356-361
نویسندگان
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