Download or read book Surface Dynamics of Si Low index Surfaces Studied by Reflection High energy Electron Diffraction written by Ibrahim El-Kholy and published by . This book was released on 2009 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Study of Surfaces by Dynamical Reflection High energy Electron Diffraction written by Tiecheng Zhao and published by . This book was released on 1990 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Dynamics written by and published by Elsevier. This book was released on 2003-11-07 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: While much of traditional surface science has been concerned with equilibrium properties and simple kinetics, there is a growing effort in the area of dynamical processes at surfaces. This book draws together a series of chapters written by acknowledged experts in the field, which describe progress in a range of specific topics. The emphasis is on chemical reaction dynamics, including both theoretical and experimental approaches and covering work on low index single crystal surfaces, on stepped surfaces and on supported metal clusters. Other processes, such as surface diffusion are also addressed. Further chapters discuss dynamical processes in electronically-induced desorption, and in surface diffusion on semiconductors and metals.- Presents considerable advances in surface science field - Collection of expert reviews in surface dynamics

Download or read book OAR Cumulative Index of Research Results written by and published by . This book was released on 1967 with total page 1264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Energy Electron Diffraction Study of Low Index Platinum Single Crystal Surfaces written by Hylan Benton Lyon and published by . This book was released on 1967 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book RHEED Studies of Vicinal Si 111 Surfaces and Ag Films Grown on Si 111 written by and published by . This book was released on 1998 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflection high energy electron diffraction (RHEED) was used to study the growth of silver films and the evolution of step structures on the silicon (111) surface. Silver films were deposited by molecular beam epitaxy onto the Si(111) 7 x 7 surface. Films deposited below room temperature showed RHEED intensity oscillation whose quality improved with decreasing temperature. RHEED oscillations were also improved by the application of an initial burst in the deposition flux. Such improvement and the temperature dependence of the oscillations is attributed to an increase in the island nucleation density. Vicinal silicon samples miscut from the (111) plane by 1.2°, 2.5°, and 4.5° towards the [2{bar 1}{bar 1}] direction were studied. If the samples were cooled slowly through the 1 x 1 to 7 x 7 phase transition a step bunching transformation would occur that produced large (111) terraces. During this transition the diffraction spot splitting would vanish while maintaining a constant splitting width. This suggest that the transition occurs by the growth of a few terraces incorporating the others with the widths of the other terraces remaining fixed until incorporation.

Download or read book RHEED Studies of Vicinal Si 111 Surfaces and Ag Films Grown on Si 111 written by Michael Kevin Stanley and published by . This book was released on 1997 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflection high energy electron diffraction (RHEED) was used to study the growth of silver films and the evolution of step structures on the silicon (111) surface. Silver films were deposited by molecular beam epitaxy onto the Si(111) 7 x 7 surface. Films deposited below room temperature showed RHEED intensity oscillation whose quality improved with decreasing temperature. RHEED oscillations were also improved by the application of an initial burst in the deposition flux. Such improvement and the temperature dependence of the oscillations is attributed to an increase in the island nucleation density. Vicinal silicon samples miscut from the (111) plane by 1.2°, 2.5°, and 4.5° towards the [2[overbar]1[overbar]1] direction were studied. If the samples were cooled slowly through the 1 x 1 to 7 x 7 phase transition a step bunching transformation would occur that produced large (111) terraces. During this transition the diffraction spot splitting would vanish while maintaining a constant splitting width. This suggest that the transition occurs by the growth of a few terraces incorporating the others with the widths of the other terraces remaining fixed until incorporation.

Download or read book High Temperature Structure Formation and Surface Diffusion of Silver on Silicon Surfaces written by Dirk Wall and published by Cuvillier Verlag. This book was released on 2012-11-21 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kurzbeschreibung Die vorliegende Arbeit beschäftigt sich mit Oberflächendiffusion und Strukturbildung an Oberflächen, speziell im Fall Silber auf Silizium. Unterschiedliche Methoden werden kombiniert um Si(001) und Si(111) Oberflächen als auch dazwischen liegende Orientierungen zu untersuchen. niedrigenergetische Elektronenmikroskopie (LEEM) und photoemissions Elektronenmikroskopie (PEEM) wurden verwendet um die Wachstumsdynamik und den Einfluss von Oberflächendiffusion auf die Strukturbildung an Oberflächen unter Ultrahochvakuum (UHV) Bedingungen zu untersuchen. Es wurden ein- und multi-kristalline Ag Inseln und selbstorganisierte Ag Drähte auf unterschiedlichen Si Oberflächen untersucht. Hierfür wurde Ag bei hohen Temperaturen auf Oberflächen aufgebracht, wobei die meisten Untersuchungen in-situ erfolgten. Die Struktur der Ag Inseln und Drähte und deren Orientierung zum Substrat wurde hauptsächlich mit niederenergetischer Elektronenbeugung an kleinen Bereichen (µ-LEED), hochauflösender niederenergetischer Elektronenbeugung (SPA-LEED) und Rasterelektronenmikroskopie (SEM) untersucht. Für die SEM Untersuchungen wurden die präparierten Proben aus dem UHV entnommen um sie in ein SEM zu transferieren und eine statistisch bessere Aussagekraft zu erreichen. Ag(001) und Ag(111) Inseln wurden bei Temperaturen von bis zu 700°C gewachsen. Mit steigender Wachstumstemperatur verändert sich die überwiegende Form der Inseln von hexagonal zu dreieckig. Die relative Drehung zum Substrat wurde Untersucht und mit einem modifizierten gitter-koinzidenz Modell (CSL) verglichen. Der Vergleich zeigt eine ausgesprochen gute Übereinstimmung der experimentellen Daten mit der Theorie, bei der praktisch alle Drehwinkel erklärt werden. Oberflächendiffusionsfelder wurden beim thermischen Zerfall und während der Desorption von Silberinseln untersucht. Um die Inseln bilden sich ein oder mehrere konzentrische rekonstruktionsbedingte Zonen. Ein einfaches kontinuum Diffusionsmodell zur Erklärung des Zerfallsmechanismus wird vorgestellt. Das Modell beinhaltet ein bereits zuvor präsentiertes Modell als einen Spezialfall und wurde in Zusammenarbeit mit J. Krug und I. Lohmar an der Universität zu Köln entwickelt. Unterschiedlichste Diffusionsparameter können mit diesem Modell bestimmt werden und stimmen sehr gut mit Literaturvergleichswerten überein. Der Zerfall der Inseln auf vizinalen Oberflächen kann nicht mehr mit diesem Modell erklärt werden, da eine Anisotropie auftritt, die die Rotationssymmetrie aufhebt. SPA-LEED Resultate zur Multistufenbildung und Facettierung sowie numerische Simulationen werden hinzugezogen und können mit Hilfe eines in der Literatur bekannten Modells praktisch alle experimentellen Daten erklären und so ein fast all-umfassendes Verständnis der Ursachen der Anisotropie erzeugen. Die Ergebnisse werden auch auf Ergebnisse zu Indium auf vizinalem Silizium angewendet und können auch hier die Überraschende Isotropie erklären. Außer den Inseln bilden sich auf Si(001) auch noch Drähte. Das Wachstum dieser Drähte wurde untersucht um eine Diskussion in der Literatur über die Ursache der Drahtbildung aufzuklären. Einkristalline Drähte wurden auf sehr genau orientiertem Si(001) und auf vizinalen Flächen präpariert. Alle Drähte orientieren sich entlang einer der beiden Hauptsymmetrierichtungen der Oberfläche. Ihr Wachstum ist thermisch aktiviert und erstaunlicherweise unabhängig von der Fehlneigung. Dennoch richten sich die Drähte mit zunehmender Fehlneigung und damit Stufendichte parallel zu den Stufenkanten aus. Die Resultate können jedoch die Diskussion ob Diffusionsanisotropie oder Verspannung die Ursache für das Drahtwachstum sind nicht aufklären, da diese zu stark ineinander überkoppeln. Dennoch kommen wir zu dem Entschluss, dass die Drahtausrichtung durch die zunehmende Diffusionsanisotropie verursacht wird. Description The present work deals with surface diffusion and structure formation, mainly for the case of Silver on Silicon surfaces. Various techniques are combined to investigate flat and vicinal surfaces oriented in the Si(001) and Si(111) directions as well as intermediate orientations. Low energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) were used to study the growth dynamics and diffusion involved in structure formation in ultrahigh vacuum (UHV) conditions. The investigated structure formation deals with single- and multi-crystalline Ag islands and self-organized Ag wires on various Si surfaces. Ag was deposited at elevated temperatures, while the investigations were mainly carried out in-situ. The structure of the grown Ag islands and wires was investigated with either small area low energy electron diffraction (µ-LEED), spot profile analyzing-low energy electron diffraction (SPA-LEED), or scanning electron microscopy (SEM). The SEM investigations were the only investigations, where the sample was extracted from the UHV and were carried out to improve the statistical significance of the data. Ag(001) and Ag(111) islands were grown at elevated temperatures of up to 700°C. With increasing growth temperature, the shape of the islands transformed from hexagonally shaped to triangular. The relative rotation to the substrate was investigated and compared to a modified coincidence site lattice approach (CSL) which agreed very well with the experimental results. Practically all of the significant rotation angles could be explained by the CSL model. Surface diffusion fields were investigated during the decay of islands in the process of desorption. These islands are surrounded by one or several concentric adsorbate induced reconstruction zones. A simple continuum diffusion model is presented, explaining the decay mechanism. The model contains a previously presented model as a special case and was developed in collaboration with J. Krug and I. Lohmar at the University of Cologne. Several diffusion parameters are extracted from the model and are in excellent agreement with values in literature. The decay of Ag islands on vicinal Si substrates no longer yields concentric circular zones, but the zones become anisotropic, and the model can no longer be applied due to the no lack of rotational symmetry. A model from the literature is used to explain the data in combination with SPA-LEED results on multi-step formation and faceting and numerical simulations. Only a combination of all these techniques is capable of a thorough and all-embracing explanation of surface diffusion. The results are compared to the system of Indium on vicinal Si(001) surfaces. Here, in contrast to Ag on vicinal Si(001), no anisotropy is found and the drawn picture can also explain the surprising diffusion isotropy. Among the islands that were used for the diffusion investigations, on Si(001), wires form. The growth of these single crystalline wires was investigated and an attempt has been taken to clear an ongoing discussion about the cause of the wire formation. The single crystalline wires were grown on flat and vicinal Si(001) surfaces. All wires align to one of the two principal directions of the substrate. Their growth is thermally activated and surprisingly independent of the substrate vicinality. The wires align with the step edges as the sample vicinality and with it the step density is increased. The results cannot lead to a clear decision on which of the discussed phenomena diffusion anisotropy or strain are the cause for self-organized wire formation on vicinal Si(001) surfaces. We can, however, come to the conclusion, that the wire alignment is much more closely linked to the diffusion anisotropy than the formation itself. We therefore state, that the diffusion anisotropy is a possible cause for the wire alignment, restricting the wire growth to one of the possible two directions with increasing diffusion anisotropy.

Download or read book Nanofabrication and Biosystems written by Harvey C. Hoch and published by Cambridge University Press. This book was released on 1996-07-13 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book also aims to stimulate innovative, productive interactions among materials scientists, engineers, and biologists, and to explore ways in which materials scientists and engineers can exploit biological principles and biological assemblies to produce new and ever smaller devices.

Download or read book Physics of Surfaces and Interfaces written by Harald Ibach and published by Springer Science & Business Media. This book was released on 2006-11-18 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate-level textbook covers the major developments in surface sciences of recent decades, from experimental tricks and basic techniques to the latest experimental methods and theoretical understanding. It is unique in its attempt to treat the physics of surfaces, thin films and interfaces, surface chemistry, thermodynamics, statistical physics and the physics of the solid/electrolyte interface in an integral manner, rather than in separate compartments. It is designed as a handbook for the researcher as well as a study-text for graduate students. Written explanations are supported by 350 graphs and illustrations.

Download or read book Chemical Abstracts written by and published by . This book was released on 1991 with total page 2682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Structural Defects in Si 100 Using Surface sensitive High resolution Electron Diffraction written by Joe Allen Martin and published by . This book was released on 1986 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Low energy Electron Diffraction Study of the Si 111 7x7 to 1x1 Phase Transition written by Peter A. Bennett and published by . This book was released on 1980 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Structures from Low Energy Electron Diffraction written by and published by . This book was released on 1995 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigated the surface bonding of various adsorbates (0, S, C2H3 and NO) along with the resulting relaxation of the Pt(111) surface using low energy electron diffiraction (LEED). LEED experiments have been performed on these ordered overlayers along with theoretical structural analysis using automated tensor LEED (ATLEED). The resulting surface structures of these ordered overlayers exhibit similar adsorbate-induced relaxations. In all cases the adsorbate occupies the fcc hollow site and induces an approximately 0.1 A buckling of the metal surface. The three metal atoms directly bonded to the adsorbate are ''pulled'' out of the surface and the metal atom that is not bound to the adsorbate is 'pushed'' inward. In order to understand the reliability of such details, we have carried out a comprehensive study of various non-structural parameters used in a LEED computation. We also studied the adsorption of water on the Pt(lll) surface. We ordered an ultra thin ice film on this surface. The film's surface is found to be the (0001) face of hexagonal ice. This surface is apparently terminated by a full-bilayer, in which the uppermost water molecules have large vibrational amplitudes even at temperatures as low as 90 K. We examined two other metal surfaces besides Pt(111): Ni(111) and Fe(lll). On Ni(111), we have studied the surface under a high coverage of NO. On both Ni(111) and Pt(111) NO molecules occupy the hollow sites and the N-0 bond distances are practically identical. The challenging sample preparation of an Fe(111) surface has been investigated and a successful procedure has been obtained. The small interlayer spacing found on Fe(111) required special treatment in the LEED calculations. A new ATLEED program has been developed to handle this surface.

Download or read book Low energy electron diffraction studies of metal and semiconductor surface written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1990 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Spectroscopy and Low Energy Electron Diffraction Studies of Silicon and Titanium Oxide Surfaces written by Yip-Wah Chung and published by . This book was released on 1977 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: