Unusual island formations of Ir on Ge (111) studied by STM

SURFACE SCIENCE

卷:666

Article

van Zifil, M.¹  Huffman, E.^1,2  Lovinger, D. J.^1,3  Chiang, S.¹ 

[1] Univ Calif Davis, Dept Phys, 1 Shields Ave, Davis, CA 95616 USA

[2] Duke Univ, Dept Phys, Durham, NC 27708 USA

[3] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA

关键词: STM;    Island formation;    Surface dislocations;    Metal-semiconductor interface;    Iridium;    Germanium;   

DOI  :  10.1016/j.susc.2017.08.016

来源: Elsevier

【 摘 要 】

Island formation on the Ir/Ge(111) surface is studied using ultrahigh vacuum scanning tunneling microscopy. Ir was deposited at room temperature onto a Ge (111) substrate with coverages between 0.5 and 2.0 monolayers (ML). The samples were annealed to temperatures between 550 and 800 K, and then cooled prior to imaging. With 1.0 ML Ir coverage, at annealing temperatures 650-750 K, round islands form at locations where domain boundaries of the substrate reconstruction intersect. Both the substrate and the islands display a (root 3x root 3)R30 degrees reconstruction. Additionally, a novel surface formation is observed where the Ir gathers along the antiphase domain boundaries between competing surface domains of the Ge surface reconstruction. This gives the appearance of the Ir in the domain boundaries forming pathways between different islands. The islands formed at higher annealing temperatures resulted in larger island sizes, which is evidence of Ostwald ripening. We present a model for the islands and the pathways which is consistent with our observations. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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