scholarly journals Reflection High-Energy Electron Diffraction (RHEED) Dynamical Theory and the Application for Adsorption and Dynamic Processes on Crystal Surfaces

Hyomen Kagaku ◽  
2010 ◽  
Vol 31 (1) ◽  
pp. 25-29
Author(s):  
Ayahiko ICHIMIYA
Keyword(s):  
Electron Diffraction ◽  
High Energy ◽  
Dynamical Theory ◽  
Energy Electron ◽  
Dynamic Processes ◽  
High Energy Electron ◽  
Crystal Surfaces

STRUCTURAL ANALYSIS OF IMPERFECT CRYSTAL SURFACES BY REFLECTION HIGH-ENERGY ELECTRON DIFFRACTION: ANTIPHASE DOMAINS OF A ${\rm Si}(111)(\sqrt 3 \times\sqrt 3)$-Ag SURFACE

1997 ◽  
Vol 04 (05) ◽  
pp. 985-990
Author(s):  
AYAHIKO ICHIMIYA ◽  
YUSUKE OHNO
Keyword(s):  
Electron Diffraction ◽  
Fourier Coefficients ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Crystal Surfaces ◽  
Domain Structures ◽  
Imperfect Crystal ◽  
Structure Determinations ◽  
Antiphase Domains

For dynamical calculations of reflection high-energy electron diffraction (RHEED) for imperfect crystal surfaces, a general formula of Fourier coefficients of crystal potential with domain structures is developed. Using the formula, RHEED intensity rocking curves are calculated for a [Formula: see text]-Ag surface with antiphase domains. We discuss effects of antiphase domains of surfaces in structure determinations by RHEED.

COMPUTATIONAL THEORY OF REFLECTION HIGH ENERGY ELECTRON DIFFRACTION

1997 ◽  
Vol 04 (03) ◽  
pp. 513-524 ◽  
Author(s):  
P. A. MAKSYM
Keyword(s):  
Electron Diffraction ◽  
High Energy ◽  
Energy Electron ◽  
Alternative Methods ◽  
Computational Techniques ◽  
Computational Technique ◽  
High Energy Electron ◽  
Crystal Surfaces ◽  
Computational Theory ◽  
The Individual

The theory of reflection high energy electron diffraction (RHEED) by crystal surfaces is reviewed, with special emphasis on computational techniques. Multiple scattering is accounted for by solving the Schrödinger equation exactly to obtain the amplitudes of the diffracted beams above the surface. The surface and substrate are divided into atomic layers and the RHEED intensities for the entire system are determined from the scattering properties of the individual layers. Alternative methods for implementing this approach are explained and compared. Recent applications to analysis of real RHEED data are used to illustrate the general theory and it is shown that it can provide very good agreement with experiment. The computational efficiency of RHEED calculations is examined carefully and key bottlenecks are identified. This leads to a new computational technique which is much faster than existing ones. Some problems connected with the implementation of this approach are examined in detail.

DETERMINATION OF LINEAR-CHAIN MULTIPLE BOUND STATE RESONANCES IN REFLECTION HIGH-ENERGY ELECTRON DIFFRACTION

1994 ◽  
Vol 01 (02n03) ◽  
pp. 261-271 ◽  
Author(s):  
T.C. ZHAO ◽  
S.Y. TONG ◽  
A. IGNATIEV
Keyword(s):  
Electron Diffraction ◽  
Bound States ◽  
Energy Levels ◽  
Linear Chain ◽  
Bound State ◽  
High Energy ◽  
Dynamical Theory ◽  
Energy Electron ◽  
High Energy Electron ◽  
Discrete Energy

Using the R-matrix dynamical theory of Reflection High-Energy Electron Diffraction (RHEED), we analyze the intensity anomalies commonly observed in RHEED rocking curves. Results for Ag(001) and Pt(111) show that the anomalies are associated with the trapping of particular components of the electron wave field inside the crystal by linear chain potential parallel to the surface. These pseudobound states correspond to minima in the total elastic flux of an ultrathin film (≤10 monolayer) and maxima in the inelastic flux. The discrete energy levels of the bound states in Ag(001) and Pt(111) are determined for the first time and the effect of such bound states on the rocking curves is discussed.

INTERPRETATION OF REFLECTION HIGH ENERGY ELECTRON DIFFRACTION FROM DISORDERED SURFACES: DYNAMICAL THEORY AND ITS APPLICATION TO THE EXPERIMENT

1999 ◽  
Vol 06 (03n04) ◽  
pp. 461-495 ◽  
Author(s):  
UWE KORTE
Keyword(s):  
Electron Diffraction ◽  
Multiple Scattering ◽  
Surface Science ◽  
Phonon Scattering ◽  
High Energy ◽  
Dynamical Theory ◽  
Energy Electron ◽  
Advanced Materials ◽  
Quantitative Interpretation ◽  
High Energy Electron

Reflection high energy electron diffraction (RHEED) is one of the few surface science techniques that are applied in a fabrication process, namely to monitor the epitaxial growth of ultrathin films and advanced materials. In spite of this technological relevance the multiple scattering nature of the involved scattering processes has hindered the quantitative interpretation of RHEED in the case of real, i.e. imperfect, surfaces for a long time. This article reviews recent progress in the understanding of RHEED from surfaces exhibiting various types of disorder. It concentrates on a multiple scattering formalism — based on perturbation theory with the nonperiodic part of the structure as perturbation — that allows the computation and interpretation of RHEED from real systems. The validity regime of the approach is discussed. We demonstrate the potential of the method by its application to the quantitative interpretation of experimental data. The range of treated problems comprises occupational disorder, intensity oscillations, structure of disordered metal/adsorbate systems, diffuse scattering from adatoms, Kikuchi scattering and phonon scattering.

Kinematic Approximations in TED and RHEED Analysis of Reconstructed Surfaces

1990 ◽  
Vol 48 (2) ◽  
pp. 396-397
Author(s):  
L. -M. Peng ◽  
M. J. Whelan
Keyword(s):  
Electron Diffraction ◽  
Kinematic Analysis ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
Great Success ◽  
High Energy Electron ◽  
Kinematic Approximation ◽  
Reconstructed Surfaces

In recent years there has been a trend in the structure determination of reconstructed surfaces to use high energy electron diffraction techniques, and to employ a kinematic approximation in analyzing the intensities of surface superlattice reflections. Experimentally this is motivated by the great success of the determination of the dimer adatom stacking fault (DAS) structure of the Si(111) 7 × 7 reconstructed surface.While in the case of transmission electron diffraction (TED) the validity of the kinematic approximation has been examined by using multislice calculations for Si and certain incident beam directions, far less has been done in the reflection high energy electron diffraction (RHEED) case. In this paper we aim to provide a thorough Bloch wave analysis of the various diffraction processes involved, and to set criteria on the validity for the kinematic analysis of the intensities of the surface superlattice reflections.The validity of the kinematic analysis, being common to both the TED and RHEED case, relies primarily on two underlying observations, namely (l)the surface superlattice scattering in the selvedge is kinematically dominating, and (2)the superlattice diffracted beams are uncoupled from the fundamental diffracted beams within the bulk.

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