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.

THERMAL, DIELECTRIC STUDIES ON PURE AND AMINO ACID (L-GLUTAMIC ACID, L-HISTIDINE, L-VALINE) DOPED POTASSIUM DIHYDROGEN PHOSPHATE SINGLE CRYSTALS

2007 ◽  
Vol 16 (02) ◽  
pp. 255-268 ◽  
Author(s):  
P. KUMARESAN ◽  
S. MOORTHY BABU ◽  
P. M. ANBARASAN
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Potassium Dihydrogen Phosphate ◽  
Lattice Parameter ◽  
Dihydrogen Phosphate ◽  
Dielectric Studies ◽  
Slow Cooling ◽  
Spectral Parameters ◽  
Potassium Dihydrogen ◽  
Good Thermal Stability

Amino acids (L-Glutamic acid, L-Histidine, L-Valine) doped potassium dihydrogen phosphate crystals were grown by the solution growth technique. Slow cooling as well as slow evaporation methods were employed to grow these crystals. The concentration of dopants in the mother solution was varied from 0.1 mole % to 10 mole %. The solubility data for all dopant concentrations were determined. The variation in pH and the corresponding habit modification of the grown crystals were characterized with UV - VIS, FT-IR and SHG trace elements, and dielectric studies reveal slight distortion of lattice parameter for the heavily doped KDP crystals. TGA-DTA studies reveal good thermal stability. The dopants increase the hardness value of the material, which also depends on the concentration of the dopants. Amino acids doping improved the NLO properties. The detailed results on the spectral parameters, habit modifications and constant values will be presented.

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.

New possibilities of the x‐ray standing wave method in multiple diffraction of synchrotron radiation

1992 ◽  
Vol 63 (1) ◽  
pp. 1019-1022 ◽  
Author(s):  
A. Yu. Kazimirov ◽  
M. V. Kovalchuk ◽  
I. Yu. Kharitonov ◽  
L. V. Samoilova ◽  
T. Ishikawa ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Standing Wave ◽  
Wave Method ◽  
Multiple Diffraction ◽  
X Ray ◽  
Standing Wave Method

Piezoelectric coefficients ofL-arginine hydrochloride monohydrate obtained by X-ray multiple diffraction using synchrotron radiation

2003 ◽  
Vol 36 (6) ◽  
pp. 1348-1351 ◽  
Author(s):  
J. M. A. Almeida ◽  
M. A. R. Miranda ◽  
C. M. R. Remédios ◽  
F. E. A. Melo ◽  
P. T. C. Freire ◽  
...  
Keyword(s):  
Amino Acid ◽  
Synchrotron Radiation ◽  
Electric Field ◽  
Equation System ◽  
Peak Position ◽  
Crystallographic Direction ◽  
Multiple Diffraction ◽  
X Ray ◽  
Arginine Hydrochloride ◽  
Hydrochloride Monohydrate

In this paper, a very useful development to improve the application of a method based on the multiple-diffraction technique to determine the piezoelectric coefficients of crystals is described. The idea is to choose any specific crystallographic direction (plane) through the secondary peaks in the Renninger scan instead of those directions related to the electric field by the piezoelectric tensor. For a set of multiple-diffraction planes, it is possible to obtain an equation system based on the ordinary peak position for eachHsecondary plane that appears in the Renninger scan. This useful development was successfully applied to the amino acid L-arginine hydrochloride monohydrate in order to provide thed21,d22,d23andd25piezoelectric coefficients by applying the electric field along the [010] crystallographic direction.

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