Structure of the orthorhombic Al13Co4(100) surface using LEED, STM, and ab initio studies

Shin, Heekeun; Pussi, K.; Gaudry, E.; Ledieu, J.; Fournée, V.; Alarcón Villaseca, S.; Dubois, J.-M.; Grin, Yuri; Gille, Peter; Moritz, Wolfgang and Diehl, R. D. (2011): Structure of the orthorhombic Al13Co4(100) surface using LEED, STM, and ab initio studies. In: Physical Review B, Vol. 84, No. 8

Abstract

In a combined scanning tunneling microscopy (STM), low-energy electrondiffraction (LEED), and density functional theory (DFT) study of thesurface of Al13Co4(100), all techniques have found that after annealingto 1165 K, the surface structure is consistent with a dense Al-richplane with surface Co atom depletion. Various structure models wereconsidered, and in the LEED study, the best agreement was found with amodel that consists of Al-rich terminating planes with no Co atoms, andotherwise a structure similar to the bulk puckered layers. Thisstructure was also found to be stable in the DFT study. The best-fitstructural parameters are presented for the two domains of thisstructure, which contain bipentagons that can be related to thepentagonal bipyramidal structures in the bulk, plus additional glueatoms between them. These domains are not strictly related to each otherby symmetry, as they have different surface relaxations. The STM studyfound significant differences in the surfaces of samples grown bydifferent methods and is able to explain a different interpretation madein an earlier study.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 550 Earth sciences and geology
• Language: English