The Experts below are selected from a list of 259923 Experts worldwide ranked by ideXlab platform
H J Ernst - One of the best experts on this subject based on the ideXlab platform.
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From meandering to faceting, is step Flow Growth ever stable?
Physical review letters, 2003Co-Authors: Nicolas Néel, T Maroutian, Ludovic Douillard, H J ErnstAbstract:Based on helium atom beam diffraction and scanning tunneling microscopy data, the coexistence of a meandering and a bunching instability during homoepitaxial step Flow Growth is established in a class of nonreconstructed,metallic vicinal surfaces, Cu (1, l, n), n = 5, 9, 17. Specifically, the meandering instability is shown to act as a precursor to the bunching instability, indicating that a one-dimensional treatment of bunching in step Flow Growth is not sufficient. Our findings might be generic to step Flow Growth in kinetically restricted systems.
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morphological instability of cu vicinal surfaces during step Flow Growth
Physical Review B, 2001Co-Authors: T Maroutian, Ludovic Douillard, H J ErnstAbstract:The step-Flow Growth of Cu on vicinal Cu surfaces, Cu (1 1 17) and Cu (0 2 24), is investigated by variable-temperature scanning-tunneling microscopy. These vicinal surfaces have identical terrace widths but their step orientation differs by 45\ifmmode^\circ\else\textdegree\fi{}. Upon Growth, the surfaces develop a step-meandering instability, resulting in an in-plane patterning of the surfaces with a temperature- and flux-dependent characteristic wavelength ${\ensuremath{\lambda}}_{u}.$ The instability-induced structural patterns depend on the step orientation and are the manifestation of the Bales-Zangwill instability in both cases. The selected characteristic wavelength is interpreted as the interplay of a destabilizing effect due to the presence of the Ehrlich-Schw\"obel barrier and a stabilizing mechanism presumably due to ``diffusion noise.'' As a result, ${\ensuremath{\lambda}}_{u}$ is proportional to the one-dimensional nucleation length ${l}_{n}$ along a straight step, involving the diffusion barrier along both the 〈110〉 and 〈100〉 step orientations on Cu(001).
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Bales-Zangwill meandering instability observed in homoepitaxial step-Flow Growth
Physical Review B, 1997Co-Authors: Ludwig Schwenger, Robert L. Folkerts, H J ErnstAbstract:The Growth of Cu on vicinal Cu templates has been investigated with helium-atom beam scattering. Step Flow on Cu (1,1,17) below room temperature forces steps to strongly meander collectively in phase, leading to the appearance of facets parallel to the average step direction. We identify this ``fingering'' with the meandering instability predicted by Bales and Zangwill, resulting from the presence of an adatom uphill current. In contrast to Cu (1,1,17), step Flow above room temperature on Cu (1,1,5) leads to a destabilization of the step train perpendicular to the step direction. Conceivable origins of this type of faceting are discussed.
Feng Liu - One of the best experts on this subject based on the ideXlab platform.
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Self-organized quantum-wire lattice via step Flow Growth of a short-period superlattice.
Physical review letters, 2004Co-Authors: Lugang Bai, Jerry Tersoff, Feng LiuAbstract:We develop a theoretical model for step Flow Growth of multilayer films, taking into account the interlayer step-step interaction induced by misfit strain. We apply the model to simulate the Growth of strain-compensated short-period superlattices. Step-bunch ordering improves in successive layers, leading to self-organized Growth of a lattice of quantum wires. This quantum-wire array has some similarities to the "lateral composition modulation" observed experimentally in short-period superlattices.
Andrew Zangwill - One of the best experts on this subject based on the ideXlab platform.
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Step-Flow Growth on strained surfaces
Applied Physics Letters, 1993Co-Authors: Christian Ratsch, Andrew ZangwillAbstract:A theoretical study is presented of the effect of misfit strain on the transition from step Flow to island nucleation dominated epitaxial layer Growth on a vicinal surface. The analysis generalizes a set of reaction‐diffusion equations used for homoepitaxy to include the fact that heteroepitaxial strain changes the Arrhenius barrier for diffusion and promotes the detachment of atoms from the edge of strained terraces and islands. The first effect is equivalent to changing the deposition flux; the latter can drive the system into a new layer Growth mode characterized by moving steps that engulf very many very small islands. Experiments to test these predictions are suggested.
Rodolfo Miranda - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of magnetic quantum wires by step‐Flow Growth of cobalt on copper surfaces
Applied Physics Letters, 1995Co-Authors: J. De La Figuera, M. A. Huerta‐garnica, José Emilio Prieto, Carmen Ocal, Rodolfo MirandaAbstract:One‐dimensional‐like Co structures 50‐A‐wide and 3000‐A‐long have been grown by decoration of the monoatomic steps of a Cu(111) surface and visualized with scanning tunneling microscopy. In order to achieve step‐Flow Growth, terrace width, evaporation rate, and substrate temperature have been carefully adjusted. The choice of the (111) terrace orientation and 〈110〉 compact steps ensures a homogeneous width of the Co wires and a lateral confinement of minority‐spin electrons.
Yoon Hee Jeong - One of the best experts on this subject based on the ideXlab platform.
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SrTiO3 homoepitaxy by the pulsed laser deposition method: island, layer-by-layer, and step-Flow Growth
Solid State Communications, 2003Co-Authors: J. H. Song, Yoon Hee JeongAbstract:Abstract SrTiO3 homoepitaxy was investigated under various conditions using the pulsed laser deposition method. The Growth mode was determined by in-situ reflection high-energy electron diffraction, and the surface of the films was characterized by ex-situ atomic force microscopy. At the laser fluence of 0.68 J/cm2, island Growth was observed below 500 °C substrate temperature, while the Growth mode turned into layer-by-layer Growth above 500 °C. On further raising the substrate temperature, the step-Flow Growth mode prevailed above 800 °C. We thus demonstrated that step-Flow Growth in SrTiO3 homoepitaxy is possible at a temperature as low as 800 °C.