Reflection High Energy Electron Diffraction Studies of the Growth of DyBa2Cu3O7−x Films and Structures Grown on SrTiO3 Substrates

1992 ◽  
Vol 275 ◽  
Author(s):  
V. S. Achutharaman ◽  
N. Chandrasekhar ◽  
A. M. Goldman
Keyword(s):  
Electron Diffraction ◽  
Specular Reflection ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
Energy Electron ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Epitaxial Relationship ◽  
Superlattice Structures

ABSTRACTIntensity oscillations of the specular reflection high energy electron diffraction (RHEED) beam contain useful information on the mode of growth and the evolving structure of thin films. We present RHEED studies of the growth of DyBa2Cu3O7−x films and DyBa2Cu3O7−x/DY2O3/DyBa2Cu3O7−x structures on SrTiO3; substrates deposited by ozone-assisted molecular beam epitaxy. The effect of substrate temperature, ozone flux and surface step densities on the epitaxial relationship and evolving microstructure will be discussed. The strong damping of the oscillations and identical time periods under different nuoleation and growth conditions suggest that the intensity oscillations are a consequence of to diffuse scattering from step edges rather than a layer-by-layer growth mode. It was also found that Dy2O3 can be used to fabricatee tri-layer type structures but not superlattice structures.

Bismuth-Induced Layer-by-Layer Growth in the Homoepitaxial Growth of Fe(100)

2002 ◽  
Vol 749 ◽  
Author(s):  
Masao Kamiko ◽  
Hiroaki Chihaya ◽  
Hiroyuki Mizuno ◽  
Junhua Xu ◽  
Isao Kojima ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Surface Segregation ◽  
High Energy ◽  
Layer Growth ◽  
Growth Behavior ◽  
Layer By Layer ◽  
High Energy Electron ◽  
Optimum Amount ◽  
Homoepitaxial Growth ◽  
Strong Surface

ABSTRACTWe have investigated the effect of Bi on the homoepitaxial growth of Fe(100) by means of reflection high-energy electron diffraction (RHEED). It was clearly found that Bi induces layer-by-layer growth of Fe on Fe(100)-c(2×2)O reconstruction surface. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is optimum amount of Bi surfactant layer that induces the smoother layer-by-layer growth. A strong surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Growth of epitaxial β-FeSi2 thin films by pulsed laser deposition on silicon (111)

1994 ◽  
Vol 9 (11) ◽  
pp. 2733-2736 ◽  
Author(s):  
C.H. Olk ◽  
O. P. Karpenko ◽  
S. M. Yalisove ◽  
G. L. Doll ◽  
J.F. Mansfield
Keyword(s):  
Electron Diffraction ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
High Energy ◽  
Layer Growth ◽  
Laser Deposition ◽  
Electron Diffraction Data ◽  
Layer By Layer ◽  
Material System ◽  
Epitaxial Relationship

Epitaxial films of semiconducting iron disilicide (β-FeSi2) have been grown by pulsed laser deposition. We find that pulsed laser deposition creates conditions favorable to the formation of films with the smallest geometric misfit possessed by this material system. In situ reflection high energy electron diffraction results indicate a layer by layer growth of the silicide. Analysis of transmission electron diffraction data has determined that the films are single phase and that this growth method reproduces the epitaxial relationship: β-FeSi2 (001) ‖ Si(111).

X-Ray Photoelectron and Auger Electron Forward-Scattering Studies of the Epitaxial Growth of Fe on Ag(100).

1991 ◽  
Vol 229 ◽  
Author(s):  
William F. Egelhoff
Keyword(s):  
Electron Diffraction ◽  
Auger Electron ◽  
High Energy ◽  
Layer Growth ◽  
Forward Scattering ◽  
Energy Electron ◽  
Atomic Step ◽  
Layer By Layer ◽  
X Ray ◽  
Place Exchange

AbstractA controversy has arisen in the past year over whether or not the growth of Fe on Ag(100) at room temperature occurs by a layer-by-layer mechanism. The present work attempts to address this controversy with an investigation of the issues, primarily by x-ray photoelectron (XPS) and Auger electron forward scattering, but with important supporting data from low-energy electron diffraction (LEED), and reflection high-energy electron diffraction (RHEED) oscillations. The results of this work suggest that the origin of the controversy lies in different substrate preparation techniques which produce different atomic step densities on the Ag(100) surface. The step sites are implicated as being the initiators of major departures from a layer-by-layer growth mode whenever most of the deposited Fe atoms have sufficient mobility to reach these steps. However, even when the Fe atoms cannot reach these steps it appears that atomic place-exchange occurs with ≥25% of the top-layer Ag atoms. Atomic place-exchange mechanisms, which could account for this intermixing, have been observed in recent molecular-dynamics simulations of epitakial growth. Thus it seems probable that under the conditions that appear to produce layer-by-layer growth, the growth begins as layer-by-layer growth of an FeAg alloy, and only becomes layer-by-layer in pure Fe as the segregating Ag atoms gradually get left behind in the growing Fe film.

Dynamical calculations for RHEED from MBE growing surfaces. I. Growth on a low-index surface

1991 ◽  
Vol 432 (1885) ◽  
pp. 195-213 ◽  
Keyword(s):  
Electron Diffraction ◽  
Molecular Beam ◽  
Diffraction Theory ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
High Energy Electron ◽  
Mbe Growth ◽  
Diffusive Growth ◽  
Almost All

Dynamical diffraction calculations have been made for reflection high-energy electron diffraction (RHEED) from molecular beam epitaxy (MBE) growing surfaces. Effects due to both the diffraction and growth conditions on the RHEED intensity oscillations during MBE growth have been investigated in detail for perfect layer growth, non-diffusive, diffusive growth, and distributed growth on a low-index surface. The results are compared with the kinematic diffraction theory, and are shown to be able to reproduce almost all features of measured RHEED intensity oscillations from low-index surfaces.

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.

Sign in / Sign up

Export Citation Format

Share Document