A two-component Frenkel–Kontorowa model for surface alloy formation

• Published in: Journal of physics. Condensed matter Vol. 15; no. 12; pp. 1827 - 1836
• Main Authors: Daruka, Istvan, Hamilton, J C
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 02.04.2003; Institute of Physics
• Subjects: Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Exact sciences and technology; Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, epr, nmr, etc.); Physics; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Gold; Phase diagrams; Heat of mixing; Digital simulation; Theoretical study; Minimization; Surface alloying; Elastic deformation; Cobalt; Dislocations; Silver; Monte Carlo methods; Transition elements; Chemical composition; Nickel; Overlayers; Frenkel Kontorova model; Copper; Defect formation
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/15/12/302

It has been shown by recent experiments that bulk immiscible metals (e.g. Ag/Cu, Ag/Co and Au/Ni) can form binary alloys on certain surfaces where the substrate mediates the elastic misfits between the two components, thus relieving the elastic strain in the overlayer. These novel surface alloys exhibit a rich phase structure. We formulate a two-component Frenkel-Kontorova model in one dimension to study surface alloy formation. This model can naturally incorporate dislocation formation that plays a crucial role in determining the actual structure of the system. Using energy minimization calculations we provide a phase diagram in terms of average alloy composition and the energy of mixing. Monte Carlo simulations were also performed to study the structure and interaction of the emerging dislocations. (An example of Ag/Cu film on Ru (0010 is shown.)