Investigation of the Homogeneity and Defect Structure in Semi-Insulating Lec GaAs Single Crystals by Synchrotron Radiation Double Crystal X-Ray Topography.

1984 ◽  
Vol 41 ◽  
Author(s):  
S J Barnett ◽  
B K Tanner ◽  
G. T. Brown
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystals ◽  
Defect Structure ◽  
Deep Level ◽  
Lattice Parameter ◽  
Double Crystal ◽  
X Ray ◽  
Lec Gaas ◽  
Order Of Magnitude ◽  
Small Lattice

AbstractThe high intensity and large beam size of a synchrotron radiation source have been exploited in order to obtain double crystal X-ray topographs of whole 2in. and 3in. slices of semi-insulating LEC GaAs single crystals. Exposure times, typically 30 minutes for high resolution topographs, are at least one order of magnitude down on those required when using a conventional source. Variations in relative lattice parameter and lattice tilt have been measured as a function of position on the slice. The defect structure has been imaged and dislocations are seen in cellular configurations, slip bands and linear arrays (lineage), the latter of which are shown to be associated with small lattice tilts, typically 30”. The defect structure revealed on the topographs has been correlated with 1μm infrared absorption micrographs which are believed to represent the concentration of the dominant deep level EL2.

Graded X-ray Optics for Synchrotron Radiation Applications

1998 ◽  
Vol 5 (3) ◽  
pp. 239-245 ◽  
Author(s):  
A. Erko ◽  
M. Veldkamp ◽  
W. Gudat ◽  
N. V. Abrosimov ◽  
S. N. Rossolenko ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Magnetron Sputtering ◽  
Single Crystals ◽  
Theoretical Data ◽  
Lattice Parameter ◽  
Structure And Properties ◽  
Czochralski Technique ◽  
Spectral Measurements ◽  
Optical Elements ◽  
X Ray

Using X-ray diffractometry and spectral measurements, the structure and properties of graded X-ray optical elements have been examined. Experimental and theoretical data on X-ray supermirrors, which were prepared by the magnetron sputtering technique using precise thickness control, are reported. Measurements on graded aperiodic Si1−x Ge x single crystals, which were grown by the Czochralski technique, are also presented. The lattice parameter of such a crystal changes almost linearly with increasing Ge concentration. The measurements indicate that Si1−x Ge x crystals with concentrations up to 7 at.% Ge can be grown with a quality comparable to that of pure Si crystals.

Quality assessment of Bridgman-grown CdTe single crystals using double-crystal X-ray diffractometry (DCD) and synchrotron radiation

2000 ◽  
Vol 210 (1-3) ◽  
pp. 193-197 ◽  
Author(s):  
R Kumaresan ◽  
R Gopalakrishnan ◽  
S Moorthy Babu ◽  
P Ramasamy ◽  
Peter Zaumseil ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Quality Assessment ◽  
Single Crystals ◽  
Double Crystal ◽  
X Ray

X-Ray Double Crystal Topography of Processed Silicon Wafers

1986 ◽  
Vol 82 ◽  
Author(s):  
Neil Loxley ◽  
Brian K. Tanner
Keyword(s):  
Synchrotron Radiation ◽  
Spatial Resolution ◽  
Lattice Parameter ◽  
Silicon Wafers ◽  
Dislocation Loops ◽  
Double Crystal ◽  
X Ray ◽  
Asymmetric Reflection ◽  
Silicon Device ◽  
Better Than

ABSTRACTDouble crystal topographs of a processed silicon device wafer, taken in highly asymmetric reflection conditions using synchrotron radiation are presented. By using a variety of wavelengths and reflections the depth and distribution of defects generated by the fabrication process are explored. Examples of several reflections are given, with a spatial resolution of better than 5 microns and extremely high device and defect visibility. Results suggest that a high mismatch of lattice parameter at device edges leads to the formation of dislocation loops penetrating junctions.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

Generation of Defects and Strain by Ion Implantation in Ge (100) Single Crystals, and in Pseudomorphic GexSi1-x Films Grown on Si (100)

1992 ◽  
Vol 262 ◽  
Author(s):  
D. Y. C. Lie ◽  
A. Vantomme ◽  
F. Eisen ◽  
M. -A. Nicolet ◽  
V. Arbet-Engels ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Defect Concentration ◽  
Double Crystal ◽  
X Ray ◽  
Positive Strain ◽  
Independent Coefficient ◽  
The Relationship ◽  
Si Ion Implantation

ABSTRACTWe have studied the damage and strain produced in Ge (100) single crystals by implantation of various doses of 300 keV 28Si ions at room temperature. The analyzing tools were x-ray double-crystal diffractometry, and MeV 4He channeling spectrometry. The damage induced by implantation produces positive strain in Ge (100). The maximum perpendicular strain and maximum defect concentration rise nonlinearly with increasing dose. These quantities are linearly related with a dose-independent coefficient of ∼ 0.013 for Ge (100) single crystals implanted at room temperature. The results are compared with those available for Si (100) self-implantation. We have also monitored the strain and defects generated in pseudomorphic Ge0.1Si0.9/Si (100) films induced by room temperature 28Si ion implantation. It is found that the relationship between the strain and defect concentration induced by ion implantation is no longer a simple linear one.

Versatile double‐crystal fixed exit monochromator for x‐ray synchrotron radiation

1995 ◽  
Vol 66 (2) ◽  
pp. 1754-1756 ◽  
Author(s):  
Mohan Ramanathan ◽  
Pedro A. Montano
Keyword(s):  
Synchrotron Radiation ◽  
Double Crystal ◽  
X Ray

Habit modification of nearly perfect single crystals of potassium dihydrogen phosphate (KDP) by trivalent manganese ions studied using synchrotron radiation X-ray multiple diffraction in Renninger scanning mode

2003 ◽  
Vol 36 (5) ◽  
pp. 1230-1235 ◽  
Author(s):  
X. Lai ◽  
K. J. Roberts ◽  
L. H. Avanci ◽  
L. P. Cardoso ◽  
J. M. Sasaki
Keyword(s):  
Synchrotron Radiation ◽  
Potassium Dihydrogen Phosphate ◽  
Lattice Parameter ◽  
Dihydrogen Phosphate ◽  
Multiple Diffraction ◽  
Lattice Contraction ◽  
X Ray ◽  
Wave Measurements ◽  
Impurity Species ◽  
Habit Modification

The X-ray multiple diffraction technique using synchrotron radiation is applied in the preliminary study of the habit modification of KDP samples as induced by incorporation of the trivalent transition metal cation Mn3+. High-resolution Renninger scans of pure and doped KDP were carried out using 400 as the primary reflection, echoing the fact that these impurity species were segregated in the {100} growth sector. The analysis of the Renninger scans of the doped KDP crystals is consistent with the presence of the impurity species chemically bound within the KDP crystal structure, as confirmed through the suppression of the huge observed peak asymmetry, characteristic of perfect crystals. In addition, an extra Renninger-scan peak measured for the doped material is indicative of the impurity atoms occupying interstitial crystallographic sites in the lattice, a result consistent with X-ray standing-wave measurements. Renninger-scan reflection curve widths and lattice parameter measurements reveal the decrease in crystalline perfection (increased mosaic spread, η) and lattice contraction ofca0.4% in theaandclattice directions at the surface plane for the Mn3+-doped KDP samples in comparison with the undoped crystals.

An accurate theory of X-ray coplanar multiple SRMS diffractometry

2018 ◽  
Vol 74 (6) ◽  
pp. 673-680 ◽  
Author(s):  
V. G. Kohn
Keyword(s):  
Synchrotron Radiation ◽  
Plane Wave ◽  
Experimental Setup ◽  
Incident Plane Wave ◽  
Instrumental Function ◽  
Multiple Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Double Crystal Monochromator ◽  
Incident Plane

The article reports an accurate theory of X-ray coplanar multiple diffraction for an experimental setup that consists of a generic synchrotron radiation (SR) source, double-crystal monochromator (M) and slit (S). It is called for brevity the theory of X-ray coplanar multiple SRMS diffractometry. The theory takes into account the properties of synchrotron radiation as well as the features of diffraction of radiation in the monochromator crystals and the slit. It is shown that the angular and energy dependence (AED) of the sample reflectivity registered by a detector has the form of a convolution of the AED in the case of the monochromatic plane wave with the instrumental function which describes the angular and energy spectrum of radiation incident on the sample crystal. It is shown that such a scheme allows one to measure the rocking curves close to the case of the monochromatic incident plane wave, but only using the high-order reflections by monochromator crystals. The case of four-beam (220)(331)({\overline {11}}1) diffraction in Si is considered in detail.

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