Optical anisotropy of quasi-1D rare-earth silicide nanostructures on Si(001)

详细信息    查看全文

• 作者：S. Chandola^a ; ^{sandhya.chandola@isas.de} ; E. Speiser^a ; N. Esser^a ; S. Appelfeller^b ; M. Franz^b ; M. Dä ; hne^b
• 关键词：Si(001) ; Rare-earth ; Nanowires ; Optical anisotropy ; Scanning tunneling microscopy
• 刊名：Applied Surface Science
• 出版年：2017
• 出版时间：31 March 2017
• 年：2017
• 卷：399
• 期：Complete
• 页码：648-653
• 全文大小：1693 K
• 卷排序：399

文摘

Reflectance anisotropy spectroscopy (RAS) is capable of distinguishing optically between the semiconducting wetting layer and the metallic nanowires of rare earth (Tb and Dy) silicide nanostructures grown on vicinal Si(001). The spectra of the wetting layer show a distinctive line shape with a large peak appearing at 3.8 eV, which is assigned to the formation of 2 × 3 and 2 × 4-like subunits of the 2 × 7 reconstruction. The spectra of the metallic nanowires show peaks at the E1 and E2 transitions of bulk Si which is assigned to strong substrate strain induced by the nanowires. The optical anisotropy of the Tb nanowires is larger than for the Dy nanowires, which is related to the preferential formation of more strained bundles as well as larger areas of clean Si surfaces in the case of Tb. RAS is shown to be a powerful addition to surface science techniques for studying the formation of rare-earth silicide nanostructures. Its surface sensitivity and rapidity of response make it an ideal complement to the slower but higher resolution of scanning probes of STM and AFM.