scholarly journals Reciprocal Space Analysis of the Initial Stages of Strain Relaxation in SiGe Epilayers

1995 ◽  
Vol 399 ◽  
Author(s):  
S. R. Lee ◽  
J. A. Floro
Keyword(s):  
Early Stage ◽  
Strain Relaxation ◽  
Geometric Model ◽  
Structural Evolution ◽  
Reciprocal Space ◽  
Displacement Fields ◽  
Diffuse Intensity ◽  
X Ray ◽  
Space Analysis ◽  
Dislocation Array

ABSTRACTMetastable SiGe films were grown by MBE on Si (001) substrates and annealed to promote varying degrees of partial relaxation. X-ray diffraction reciprocal-space analysis was then used to monitor the structural evolution of the displacement fields of the dislocation array with increasing misfit density. The diffuse-x-ray-scattering patterns of the dislocated heterolayers were compared with lineal-misfit densities determined by defect etching, leading us to develop a geometric model which provides a framework for understanding the early-stage evolution of the displacement fields of the dislocation array, and which also explicitly links diffuse x-ray intensity to misfit density. At low misfit density, the diffuse intensity arises from two-dimensional displacement fields associated with single-nonoverlapping dislocations. As misfit density increases, the displacement fields of individual dislocations increasingly overlap producing three-dimensional displacements. The evolving diffuse intensity reflects the transition from 2-D to 3-D displacement fields. Finally, it is demonstrated that the diffuse x-ray intensity of the strained epilayer can be used to accurately measure lineal misfit-dislocation densities from 400 to 20,000 lines/cm.

X‐ray reciprocal‐space mapping of strain relaxation and tilting in linearly graded InAlAs buffers

1996 ◽  
Vol 79 (7) ◽  
pp. 3578-3584 ◽  
Author(s):  
J. A. Olsen ◽  
E. L. Hu ◽  
S. R. Lee ◽  
I. J. Fritz ◽  
A. J. Howard ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Reciprocal Space Mapping ◽  
X Ray

X-Ray Investigation of Strain Relaxation in Short-Period SimGen Superlattices using Reciprocal Space Mapping

1993 ◽  
Vol 298 ◽  
Author(s):  
P. Hamberger ◽  
E. Koppensteiner ◽  
G. Bauer ◽  
H. Kibbel ◽  
H. Presting ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Reciprocal Lattice ◽  
Reciprocal Space ◽  
Lattice Points ◽  
Reciprocal Space Mapping ◽  
Double Crystal ◽  
X Ray ◽  
Short Period ◽  
Integrated Intensity ◽  
Strained Layer Superlattices

AbstractThe optoelectronic properties of SimGen strained layer superlattices (SLS's) depend strongly on the structural perfection. We used double crystal and triple axis x-ray diffractometry to characterize the structural properties of short period Si9Ge6 SLS's grown on about lμm thick step-graded SiGe alloy buffers. As grown SLS's and samples annealed subsequently at 550°C, 650°C and 780°C for 60 mmn were investigated. Precise strain data were extracted from two-dimensional reciprocal space maps around (004) and (224) reciprocal lattice points. These data were used as refined input parameters for the dynamical simulation of the integrated intensity along the qll[004] direction. Annealing causes interdiffusion as indicated by the decreasing superlattice (SL)-satellite peak intensities and by the change of the Si/Ge thickness ratio. However, the full width at half maximum of the SL satellite peaks does not change significantly with annealing up to 650°C. The in-plane SL lattice constant in both samples is increased only slighty by annealing (< 9×10−3 Å). Consequently the interface intermixing due to interdiffusion is the main cause for the shift of the luminescence energy to higher values in these annealed samples.

Study of the early Stage of Deposition Process for Electrodeposited Ni100-XFeX Thin Films

2011 ◽  
Vol 495 ◽  
pp. 1-4 ◽  
Author(s):  
Saci Messaadi ◽  
Mosbah Daamouche ◽  
Abderrahim Guittoum ◽  
Hadria Medouer ◽  
Noureddine Fenineche ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electrochemical Method ◽  
Early Stage ◽  
Structural Evolution ◽  
Deposition Process ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
Nucleation Kinetics ◽  
Theoretical Methods ◽  
X Ray

The aim of this work is to understand the early stages in the growth mechanism of invar (Fe64Ni34) alloys and also to study the influence of potential on the evolution of their crystalline structures. Fe64Ni34 layers were deposited onto copper substrates under optimal conditions using the electrochemical method of cyclic voltammetry (CV) and chronoamperometry (CA). The influence of the potential is examined and the nucleation kinetics is discussed. In this purpose, the obtained experimental data was interpreted by applying useful theoretical methods developed by Scharifker and Hills. X-ray diffraction experiments were performed on all samples in order to follow the structural evolution of Fe64Ni34 layers as a function of the potential.

scholarly journals Erratum: “X-ray reciprocal space mapping of dislocation-mediated strain relaxation during InGaAs/GaAs(001) epitaxial growth” [J. Appl. Phys. 110, 113502 (2011)]

2013 ◽  
Vol 113 (19) ◽  
pp. 199901
Author(s):  
Takuo Sasaki ◽  
Hidetoshi Suzuki ◽  
Masamitu Takahasi ◽  
Yoshio Ohshita ◽  
Itaru Kamiya ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Strain Relaxation ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Reciprocal Space Mapping ◽  
X Ray

X-ray reciprocal space mapping of dislocation-mediated strain relaxation during InGaAs/GaAs(001) epitaxial growth

2011 ◽  
Vol 110 (11) ◽  
pp. 113502 ◽  
Author(s):  
Takuo Sasaki ◽  
Hidetoshi Suzuki ◽  
Masamitu Takahasi ◽  
Yoshio Ohshita ◽  
Itaru Kamiya ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Strain Relaxation ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Reciprocal Space Mapping ◽  
X Ray

scholarly journals Micro/nano-structural evolution in spruce wood during soda pulping

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ahmed Wagih ◽  
Merima Hasani ◽  
Stephen A. Hall ◽  
Hans Theliander
Keyword(s):  
Large Scale ◽  
Structural Information ◽  
Early Stage ◽  
Morphological Changes ◽  
Structural Evolution ◽  
Wood Tissue ◽  
X Ray ◽  
Alkaline Pulping ◽  
Soda Pulping ◽  
Alkaline Delignification

Abstract Alkaline delignification of wood tissue is the core of the global pulping technology and the most prominent large-scale separation of the main wood components. This work aims at improved understanding of the interplay between the topochemistry of alkaline pulping and the associated morphological changes. Morphology and chemical structure of partially soda-delignified wood chips were studied combining X-ray tomography (XRT), X-ray diffraction analysis and compositional characterization (lignin and carbohydrate content). The XRT studies of wet samples (providing 3D structural information without interfering drying effects), allowed observation of the cell wall separation as an increasing amount of lignin was removed with the increasing pulping time. Comparison between the microstructure of the surface and the central parts of the treated chips showed a more delignified microstructure at the surface, which highlights the dependence of the delignification process on the mass transport (hydroxide ions and lignin fragments) through the wood tissue. The crystallite size of cellulose increased in the <200> crystal planes during the early stage of pulping while there was little effect on the <110> plane.

scholarly journals Reciprocal Space Analysis of the Microstructure of Luminescent and Nonluminescent Porous Silicon Films

1994 ◽  
Vol 358 ◽  
Author(s):  
S.R. Lee ◽  
J.C. Barbour ◽  
J.W. Medernach ◽  
J.O. Stevenson ◽  
J.S. Custer
Keyword(s):  
Porous Silicon ◽  
Space Structure ◽  
Reciprocal Space ◽  
Silicon Films ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Crystalline Materials ◽  
X Ray ◽  
Space Analysis ◽  
Spatially Correlated

ABSTRACTThe microstructure of anodically prepared porous silicon films was determined using a novel x-ray diffraction technique. This technique uses double-crystal diffractometry combined with position-sensitive x-ray detection to efficiently and quantitatively image the reciprocal space structure of crystalline materials. Reciprocal space analysis of newly prepared, as well as aged, p+ porous silicon films showed that these films exhibit a very broad range of crystallinity. This material appears to range in structure from a strained, single-crystal, sponge-like material exhibiting long-range coherency to isolated, dilated nanocrystals embedded in an amorphous matrix. Reciprocal space analysis of n+ and p+ porous silicon showed these materials are strained single-crystals with a spatially-correlated array of vertical pores. The vertical pores in these crystals may be surrounded by nanoporous or nanocrystalline domains as small as a few nm in size which produce diffuse diffraction indicating their presence. The photoluminescence of these films was examined using 488 nm Ar laser excitation in order to search for possible correlations between photoluminescent intensity and crystalline microstructure.

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