Modeling impurity-assisted chain creation in noble-metal break junctions

• Published in: Journal of physics. Condensed matter Vol. 24; no. 13; pp. 135501 - 19
• Main Authors: Napoli, S Di, Thiess, A, Blügel, S, Mokrousov, Y
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 04.04.2012; Institute of Physics
• Subjects: Bonding; Bonding strength; Breaking; Carbon - chemistry; Chains; Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper - chemistry; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Formations; Gold Alloys - chemistry; Hydrogen - chemistry; Impurities; Impurity and defect levels; energy states of adsorbed species; Materials Testing; Mathematical models; Models, Molecular; Nitrogen - chemistry; Oxygen - chemistry; Physics; Silver - chemistry; Surface and interface electron states; Gold; Total energy; Surface electron state; Break junction; APW calculations; Silver; Impurities; Binding energy; One dimensional model; Density functional method; Adatoms; Copper; Local density approximation
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/24/13/135501

In this work we present the generalization of the model for chain formation in break junctions, introduced by Thiess et al (2008 Nano Lett. 8 2144), to zigzag transition-metal chains with s and p impurities. We apply this extended model to study the producibility trends for noble-metal chains with impurities, often present in break junction experiments, namely, Cu, Ag and Au chains with H, C, O and N adatoms. Providing the material-specific parameters for our model from systematic full-potential linearized augmented plane-wave first-principles calculations, we find that the presence of such impurities crucially affects the binding properties of the noble-metal chains. We reveal that both the impurity-induced bond strengthening and the formation of zigzag bonds can lead to a significantly enhanced probability for chain formation in break junctions.