Alloy Surface Structure Research Articles

Surface electronic structure of clean and hydrogen-chemisorbed SixGe1-x alloy surfaces.

Surface electronic structure of clean and hydrogen-chemisorbed SixGe1-x alloy surfaces.

An experimental study of the growth of Co/Pt(111) by core level photoemission spectroscopy, low-energy electron diffraction and Auger electron spectroscopy

We have analysed by use of synchrotron radiation induced angle resolved photoemission spectroscopy (PES), Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED) the growth of ultrathin Co layers deposited at room temperature on Pt(111) surfaces. The LEED patterns indicate an incoherent epitaxy and AES data can be explained by a near layer by layer growth mode. Decomposition of the Pt 4f7/2 photoemission line shows characteristic core level shifts for the different environments of Pt atoms, giving insight concerning a relatively sharp interface structure. On the other hand, the Pt/Co interface in the Pt/Co/Pt(111) sandwich is less sharp, giving rise to two Pt surface sites. Annealing of the Co/Pt(111) system at 400 degrees C gives a surface alloy structure with the same symmetry and orientation as the Pt substrate.

Chemical and Topological Structure of Alloy Surfaces: From Equilibrium to Kinetics

Chemical and Topological Structure of Alloy Surfaces: From Equilibrium to Kinetics

Surface and bulk equilibrium structures of silicon-germanium alloys from Monte Carlo simulations

The technologically important alloy of silicon and germanium is known to have no long-range order in the bulk. Whether there is any short-range order in the bulk and the nature of the structure of the surface and near-surface regions remains the subject of some debate. We present a method of Monte Carlo simulation that is effective for studying the equilibrium structural properties of the bulk and strained-superlattice alloys. The simulations of the bulk alloy indicate that there is no short-range order and that the Si-Ge alloy is a true random alloy at room temperature and above. The surfaces of these alloys experience segregation of germanium to the surface, with no long-range order observed in the slightly silicon-rich subsurface layers, in agreement with recent experiments.

The adhesion mechanism of dental adhesive resin to the alloy. Relationship between CoCr alloy surface structure analysed by ESCA and bonding strength of adhesive resin

The adhesion mechanism of dental adhesive resin to the alloy. Relationship between CoCr alloy surface structure analysed by ESCA and bonding strength of adhesive resin

Atomic Structure of Binary Alloy Surfaces

ABSTRACTAfter discussions of multilayer relaxation for monatomic metallic surfaces and low-energy electron diffraction (LEED) procedures, some available results concerning the atomic structure of alloy surfaces are reviewed briefly. Results are discussed only for surfaces of ordered binary alloys and crystalline, substitutionally random binary alloys. Surfaces for which detailed results are available are highlighted as examples which illustrate some general crystallographic effects that occur at alloy surfaces. Specific effects included in the examples are the rippling of atomic constituents in the surface layers of ordered alloys, the preferential termination of alloys by a specific type of layer where more than one type of layer exists in the bulk, a mixture of two possible terminations, and the alternating enrichment and depletion of an atomic constituent in the surface layers of alloys which are disordered in the bulk.

A model calculation on the electronic structure of Ni-Cu and Pd-Ag alloys

The electronic structure of Ni-Cu and Pd-Ag alloy surfaces is investigated by the CNDO/2 tight-binding method. In both alloys, the VIIIB and IB metal atoms form the independent d sub-bands, which is qualitatively consistent with the calculations by the coherent-potential approximation and with photoemission spectroscopy experiments.

ChemInform Abstract: ELECTRONIC STRUCTURE OF METAL AND ALLOY SURFACES

Chemischer InformationsdienstVolume 10, Issue 39 Reviews ChemInform Abstract: ELECTRONIC STRUCTURE OF METAL AND ALLOY SURFACES K. H. JOHNSON, K. H. JOHNSONSearch for more papers by this authorC. Y. YANG, C. Y. YANGSearch for more papers by this authorD. VVEDENSKY, D. VVEDENSKYSearch for more papers by this authorR. P. MESSMER, R. P. MESSMERSearch for more papers by this authorD. R. SALAHUB, D. R. SALAHUBSearch for more papers by this author K. H. JOHNSON, K. H. JOHNSONSearch for more papers by this authorC. Y. YANG, C. Y. YANGSearch for more papers by this authorD. VVEDENSKY, D. VVEDENSKYSearch for more papers by this authorR. P. MESSMER, R. P. MESSMERSearch for more papers by this authorD. R. SALAHUB, D. R. SALAHUBSearch for more papers by this author First published: September 25, 1979 https://doi.org/10.1002/chin.197939317AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue39September 25, 1979 RelatedInformation

Surface structures of CuAu and CuPd alloys as observed by leed

Surface structures are studied by LEED in Cu−Au and Cu−Pd alloy systems and compared with those expected from the bulk ordered structures of Cu 3Au(Cu 3Pd(α′)), CuAuI and CuPd(β). The c(2×2) structure on the {100} surface of CuAu and CuPd systems seems to agree with the sections of Cu 3Au and Cu 3Pd(α′), respectively. The (2×1) structure on the {110} surface of CuPd system has the same periodicity as that in the section of Cu 3Pd(α′) and the (2×2) structure on the {111} surface of CuAu system is considered to correspond to the section of the CuAuI structure. Characteristic surface structures such as (1×2), complex, c(3×1), and (2×2) on the {110} surface and ( 2 3 √3 × 2 3 √3 )R30° on the {111} surface are observed for the CuAu system, which are not expected from the sections of the bulk ordered structures.

A surface analysis of CuAu alloy by leed and Auger electron spectroscopy

Surface structures and compositions of the CuAu alloys have been investigated, which were prepared by depositing gold on (110) and (111) surfaces of copper and by subsequent heating. By this method the structure of alloy surfaces corresponding to different compositions can be observed by LEED. A series of the LEED patterns, streak, (1 × 2), (1 × 1)I, complex, c(3 × 1), (1 × 1)II, (2 × 2) and (1 × 1) have been observed on the (110) surface with decreasing gold composition. On the (111) surface (1 × 1) pattern, weak (2/√3 × 2/√3) R30° and (2 × 2) patterns are observed. The mean surface composition is determined by analysing the data of Auger electron spectroscopy. Most surface periodicities observed are different from those expected if one passes a mathematical plane through the crystal (unreconstructed surface).

Electronic structure of alloy surfaces: Coherent-potential approximation

The electronic structure of alloy surfaces is investigated within the framework of the coherent-potential approximation, a scheme originally derived for infinite alloy systems and here generalized to the case of the semi-infinite cleaved alloy crystal. The theory is applied to substitutional binary alloys, described by a single-band Wannier model one-electron Hamiltonian. Numerical results for the configurationally averaged surface density of states are discussed for a variety of system parameters. Among the cases considered are alloys of uniform composition and alloys in which the surface composition differs from that of the interior.

Comments on “determination of nickel-molybdenum surface alloy structures using LEED” by L.G. Feinstein and E. Blanc

Comments on “determination of nickel-molybdenum surface alloy structures using LEED” by L.G. Feinstein and E. Blanc