X-Ray Studies of GaAs/Si and ZnS/Si

1988 ◽  
Vol 144 ◽  
Author(s):  
H. M. Kim ◽  
Y-W Choi ◽  
S. Vernon ◽  
P. S. Moise ◽  
C. R. Wie
Keyword(s):  
Phase Contrast ◽  
Lattice Mismatch ◽  
Phase Contrast Microscopy ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Dislocation Densities ◽  
Contrast Microscopy ◽  
Expansion Coefficients

ABSTRACTThe MOCVD-grown layers of GaAs/Si(001), InP/GaAs/Si(001), and ZnS/Si(111) were studied using X-ray rocking curve (XRC), double crystal topography (DCT), and Nomarski phase contrast microscopy. The layer qualities of GaAs/Si, InP/GaAs, and InP/GaAs/Si from the XRC full width at half maximum (FWHM) agreed well with these determined from the Nomarski phase contrast microscopy. The in-plane lattice mismatch (parallel X-ray strain) was 3.71% for GaAs/Si. In the double heteroepitaxial layer (InP/GaAs/Si), the parallel X-ray strain of GaAs was 4.03% with respect to Si. The parallel X-ray strain was larger than the perpendicular X-ray strain in GaAs/Si, perhaps due to the mismatch in thermal expansion coefficients between GaAs and Si. Dislocation densities estimated from the rocking curve linewidth were 5.30 × 107 cm−2 for GaAs/Si, 3.27 × 108 cm−2 for InP/GaAs. We also present the double crystal X-ray topographs of the III-V/Si and II-VI/Si samples.

scholarly journals Observation of subnanometre-high surface topography with X-ray reflection phase-contrast microscopy

2006 ◽  
Vol 2 (10) ◽  
pp. 700-704 ◽  
Author(s):  
Paul Fenter ◽  
Changyong Park ◽  
Zhan Zhang ◽  
Steve Wang
Keyword(s):  
Surface Topography ◽  
Phase Contrast ◽  
High Surface ◽  
Phase Contrast Microscopy ◽  
X Ray ◽  
Reflection Phase ◽  
Contrast Microscopy

High-resolution hard X-ray phase-contrast microscopy with a large-diameter and high-numerical-aperture zone plate

2002 ◽  
Vol 9 (3) ◽  
pp. 132-135 ◽  
Author(s):  
Yasushi Kagoshima ◽  
Yoshiyuki Yokoyama ◽  
Takashi Ibuki ◽  
Toshihiro Niimi ◽  
Yoshiyuki Tsusaka ◽  
...  
Keyword(s):  
High Resolution ◽  
Phase Contrast ◽  
Large Diameter ◽  
Numerical Aperture ◽  
Zone Plate ◽  
Phase Contrast Microscopy ◽  
X Ray ◽  
High Numerical Aperture ◽  
Contrast Microscopy

scholarly journals Phase-contrast microscopy at high x-ray energy with a laboratory setup

2014 ◽  
Vol 39 (11) ◽  
pp. 3332 ◽  
Author(s):  
Marco Endrizzi ◽  
Fabio A. Vittoria ◽  
Paul C. Diemoz ◽  
Rodolfo Lorenzo ◽  
Robert D. Speller ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Phase Contrast Microscopy ◽  
X Ray ◽  
Laboratory Setup ◽  
Contrast Microscopy

X-Ray Double Crystal Diffraction Characterization of Epitaxial Magnetic Transiton Metal Difluorides

1990 ◽  
Vol 187 ◽  
Author(s):  
M. Lui ◽  
A. R. King ◽  
V. Jaccarino ◽  
R. F. C. Farrow ◽  
S. S. P. Parkins
Keyword(s):  
Lattice Mismatch ◽  
Magnetic Transition ◽  
Diffraction Theory ◽  
Epitaxial Films ◽  
Structural Quality ◽  
Double Crystal ◽  
Lattice Match ◽  
Rocking Curve ◽  
X Ray ◽  
Quality Material

AbstractEpitaxial films of a variety of magnetic transition metal difluoride films have been grown by molecular beam epitaxy techniques. The structural quality of these films have been characterized using X-ray double crystal rocking curve analysis. The observed rocking curve linewidths were compared to their intrinsic values as calculated by dynamical diffraction theory. The degree of crystalline perfection as judge by the rocking curves have been correlated with the amount of lattice mismatch between the various epitaxial films and substrates. In the well lattice match case (Δa/a < 0.2%) of epitaxial films of FeF2 and CoF2 grown on (001) ZnF2 substrates, the rocking curve line widths approached their intrinsic limit indicative of extremely high quality material. This work represents some of the best epitaxial magnetic insulating films grown to date.

10 keV X-Ray Phase-Contrast Microscopy for Observing Transparent Specimens

2001 ◽  
Vol 40 (Part 2, No. 11A) ◽  
pp. L1190-L1192 ◽  
Author(s):  
Yasushi Kagoshima ◽  
Takashi Ibuki ◽  
Yoshiyuki Yokoyama ◽  
Yoshiyuki Tsusaka ◽  
Junji Matsui ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Phase Contrast Microscopy ◽  
X Ray ◽  
Contrast Microscopy

Measurement of Elastic Lattice Distortion in PbTe/PbSnTe - Strained Layer Superlatices by Asymmetric High Angle X-ray interfernces

1985 ◽  
Vol 29 ◽  
pp. 367-374
Author(s):  
E. J. Fantner
Keyword(s):  
Elastic Strain ◽  
Lattice Mismatch ◽  
Strain Tensor ◽  
Misfit Strain ◽  
High Angle ◽  
Double Crystal ◽  
X Ray ◽  
Strained Layer ◽  
Thermal Expansion Coefficients ◽  
Quaternary Compounds

AbstractElastic strain significantly affects the electric and optical properties of PbTe/Pb1-xSnxTe - strained-layer superlattices. In the range of 10 - 350K the temperature dependence of the elastic strain present in these superlattices was measured by double-crystal x-ray diffraction. For superlattice periods smaller than 100nm High-angle x-ray interferences were observed. Using a novel method, which makes use of the High-angle interferences both for symmetrical as well as for asymmetrical reflections in a theta-twotheta scan with a narrow detector slit, the relative inclination of equivalent lattice planes due the elastic strain was measured. The components of the complete strain tensor of the constituent layers can be determined seperately even if their unstrained lattice constants are not known with sufficient accuracy as is the case in ternary and quaternary compounds. The lattice mismatch of up to 0.4% for Sn-contents smaller than 20% was found to be accommodated almost completely by elastic misfit strain. The amount of strain is shared between the constituent layers inversely to their relative thicknesses as long as the superlattice as a whole is much thicker than the buffer layer. Below room temperature an additional temperature dependent tensile strain due to differnt thermal expansion coefficients of the film and the BaF2-substrate is measured quantitatively.

Hard x-ray quantitative non-interferometric phase-contrast microscopy

1999 ◽  
Vol 32 (5) ◽  
pp. 563-567 ◽  
Author(s):  
T E Gureyev ◽  
C Raven ◽  
A Snigirev ◽  
I Snigireva ◽  
S W Wilkins
Keyword(s):  
Phase Contrast ◽  
Phase Contrast Microscopy ◽  
X Ray ◽  
Interferometric Phase ◽  
Contrast Microscopy

Quantitative phase retrieval in X-ray Zernike phase contrast microscopy

2015 ◽  
Vol 22 (4) ◽  
pp. 1056-1061 ◽  
Author(s):  
Heng Chen ◽  
Zhili Wang ◽  
Kun Gao ◽  
Qiyue Hou ◽  
Dajiang Wang ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Phase Retrieval ◽  
Materials Science ◽  
Phase Contrast Microscopy ◽  
Contrast Imaging ◽  
X Ray ◽  
Quantitative Phase ◽  
Direct Light ◽  
Contrast Microscopy ◽  
Phase Variations

In recent years, increasing attention has been devoted to X-ray phase contrast imaging, since it can provide high-contrast images by using phase variations. Among the different existing techniques, Zernike phase contrast microscopy is one of the most popular phase-sensitive techniques for investigating the fine structure of the sample at high spatial resolution. In X-ray Zernike phase contrast microscopy, the image contrast is indeed a mixture of absorption and phase contrast. Therefore, this technique just provides qualitative information on the object, which makes the interpretation of the image difficult. In this contribution, an approach is proposed for quantitative phase retrieval in X-ray Zernike phase contrast microscopy. By shifting the phase of the direct light by π/2 and 3π/2, two images of the same object are measured successively. The phase information of the object can then be quantitatively retrieved by a proper combination of the measured images. Numerical experiments were carried out and the results confirmed the feasibility of the proposed method. It is expected that the proposed method will find widespread applications in biology, materials science and so on.

X-Ray Strain Measurements in IV-VI Semiconductor Super-Lattices at Low Temperature

1983 ◽  
Vol 27 ◽  
pp. 171-178 ◽  
Author(s):  
E.J. Fantner ◽  
H. Clemens ◽  
G. Bauer
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Tensile Strain ◽  
Room Temperature ◽  
Lattice Mismatch ◽  
Misfit Strain ◽  
Strain Measurements ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

AbstractMultilayers composed of many thin films of PbTe and Pb1-xSnxTe on BaF2 substrates were grown epitaxially by hot-wall-vapor deposition. In order to investigate the fraction of the total misfit (2.5x10-3 at x=O, 12) accommodated by misfit strain we have performed strain measurements on these superlattices by two different X-ray diffractometer techniques. We also report on substrate induced strain due to different thermal expansion coefficients of films and substrate. For film thicknesses smaller than 300 nm there is clear evidence for almost complete accommodation of lattice mismatch by misfit strain. Below room temperature the substrate induces a tensile strain which is comparable to that of the misfit strain.

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