Manifestations of strain–relaxation in the structure of nano-sized Co-2×2 islands grown on Ag/Ge(111)-√3×√3 surface

• Published in: Thin solid films Vol. 520; no. 16; pp. 5304 - 5308
• Main Authors: Huang, Xiao-Lan, Tomaszewska, Agnieszka, Lin, Chun-Liang, Tsay, Sung-Lin, Chou, Chi-Hao, Fu, Tsu-Yi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2012
• Subjects: Growth; Scanning tunneling microscopy; Strain; Scanning tunneling microscopy; Co; Growth; Ag; Ge; Strain
• DOI: 10.1016/j.tsf.2012.03.126
• ISSN: 0040-6090

We have examined strain–relaxation of Co-2×2 islands grown on the Ag/Ge(111)-√3×√3 surface by analyzing scanning tunneling microscopy images. We have found that the Co-2×2 islands commonly adopt a more compact arrangement as compared to that of the Ge(111) substrate, however they differ in a degree of an atomic compactness. We have not found a distinct relation between strain–relaxation and the island height. Three groups of islands have been identified upon analyzing a correspondence between strain–relaxation and the island size: (i) small islands (not bigger than 80nm2) with a high atomic compactness, displaying fixed inter-row distances, (ii) small islands with unfixed distances between atomic rows, and (iii) big islands (bigger than 80nm2) with fixed inter-row distances, but with a less compact atomic arrangement compared to that of the first two groups. We propose a model to account for the relation between the relaxation and the island size. ► We examine strain–relaxation of Co-2×2 islands grown on Ag/Ge(111)-√3×√3 surface. ► The Co-2×2 islands are more compact as compared to the substrate. ► No relation between the relaxation and the island height. ► Atomic compactness and atomic order as manifestations of strain–relaxation.