Charging Effects on the Adsorption and Diffusion of Au Adatoms on MgO(100)

• Published in: Journal of the Physical Society of Japan Vol. 90; no. 3; p. 34602
• Main Authors: Park, Jong Hwan, Yang, Jeong Woo, Byun, Min Gyo, Hwang, Nong Moon, Park, Jinwoo, Yu, Byung Deok
• Format: Journal Article
• Language: Japanese; English
• Published: Tokyo Physical Society of Japan 15.03.2021; The Physical Society of Japan
• Subjects: Adatoms; Adsorption; Chemical bonds; Diffusion barriers; General Physics and Astronomy; Magnesium oxide; Surface chemistry; Surface diffusion
• ISSN: 0031-9015; 1347-4073
• DOI: 10.7566/jpsj.90.034602

By ab initio calculations, the adsorption and diffusion properties of positively charged Au+ and negatively charged Au− adatoms on defect-free MgO(100) surfaces were investigated and compared with the case of charge-neutral Au0 on MgO(100). Our results showed that the most stable adsorption site of Au+ on MgO(100) is atop the O site, as per Au0, whereas that of Au− on MgO(100) is atop the Mg site. Our results showed a surface diffusion barrier of Au+ on MgO(100) of 0.30 eV, which is larger than that (0.25 eV) of Au0. For Au−, the surface diffusion barrier is as low as 0.03 eV. Further detailed analyses of the charge rearrangement, Bader charges, electronic structures, and characteristics of the atomic bonds were also performed. These results emphasize the significant roles of the charge states of Au adatoms in the adsorption and diffusion properties of Au on MgO(100).