Study of the influence of dopants on the crystalline perfection of ferroelectric glycine phosphite single crystals using high-resolution X-ray diffraction analysis

Good quality and optically transparent single crystals of pure and doped glycine phosphite (GPI) were grown by both solvent-evaporation and temperature-cooling techniques. Dopants were chosen in different categories, namely transition metals (Cr, Mn, Co, Ni, Zn, Mg, Cd), rare-earth metals (Ce, Nd, La), dyes (rhodamine B, malachite green, fluorescein) and an amino acid (L-proline). The concentration of dopants was chosen depending on the category of dopants and the quality of crystallization during the growth process. The crystalline perfection of the as-grown pure and doped GPI crystals was investigated by high-resolution X-ray diffraction at room temperature. A multicrystal X-ray diffractometer employing a well collimated and highly monochromated Mo Kα1beam and set in the (+, −, −, +) configuration was employed. Most of the crystal specimens show excellent crystalline perfection. However, grain boundaries, low-angle tilt boundaries, and vacancy and interstitial point defects were observed in some crystal specimens.

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Effect of crucible design on crystalline perfection and the enhanced optical properties of benzimidazole single crystals grown by the vertical Bridgman technique

Journal of Applied Crystallography ◽

10.1107/s0021889812050297 ◽

2013 ◽

Vol 46 (1) ◽

pp. 276-278 ◽

Cited By ~ 13

Author(s):

B. Riscob ◽

N. Vijayan ◽

Mohd Shakir ◽

M. A. Wahab ◽

G. Bhagavannarayana

Keyword(s):

Optical Properties ◽

Melting Point ◽

High Resolution ◽

Single Crystals ◽

X Ray Diffraction ◽

Crystalline Perfection ◽

Bridgman Technique ◽

X Ray ◽

Vertical Bridgman ◽

Double Wall

Good quality benzimidazole (BMZ) single crystals were successfully grown by the vertical Bridgman technique (VBT). The unavoidable thermal-induced structural grain boundaries formed in the normal VBT growth of these crystals with low melting point were controlled by using a double-wall ampoule. The grown single crystals were subjected to high-resolution X-ray diffraction to assess their crystallinity. The enhancement of optical properties due to the improvement in crystalline perfection is also reported.

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A study of as-grown, poled and reduced Rh-doped KNbO3 single crystals by high-resolution X-ray diffraction, Raman scattering, photoluminescence and dielectric measurements

Journal of Applied Crystallography ◽

10.1107/s1600576714012758 ◽

2014 ◽

Vol 47 (4) ◽

pp. 1324-1328 ◽

Cited By ~ 1

Author(s):

G. Bhagavannarayana ◽

A. Choubey ◽

S. K. Kushwaha ◽

S. N. Sharma ◽

R. Rani ◽

...

Keyword(s):

High Resolution ◽

Raman Scattering ◽

Single Crystals ◽

Chemical Reduction ◽

Great Influence ◽

Excess Oxygen ◽

X Ray Diffraction ◽

High Concentration ◽

Crystalline Perfection ◽

X Ray

As-grown and chemically reduced Rh-doped (1500 p.p.m.) KnbO3 single crystals grown by the Czochralski method have been characterized. Reduction of the grown crystals at different levels was carried out under a mixture of CO and CO2 gases as the crystals were grown with excess oxygen. The effect of reduction and poling on crystalline perfection was studied by high-resolution X-ray diffraction (HRXRD) using a multi-crystal X-ray diffractometer developed in-house. The diffraction curves of the as-grown, electrically poled, moderately reduced and heavily reduced single-crystal specimens show remarkable differences. The studies by HRXRD reveal that poling has some influence on the improvement of crystalline perfection, while chemical reduction has a great influence on crystalline perfection; at moderate reduction the crystal becomes nearly perfect, but when the reduction is very heavy the crystal quality decreases slightly, although it is still better than for unreduced samples. Asymmetry of the diffraction curves with respect to the peak position reveals that the as-grown specimens contain a high concentration of both vacancies and self-interstitials. After poling, the concentration of self-interstitial defects is lowered to some extent. When the specimen is moderately chemically reduced, the scattered intensity on both sides of the peak is greatly reduced, showing that the concentrations of both vacancies and interstitials are reduced to a great extent owing to chemical reduction. This clearly indicates that, as a result of the chemical reduction of oxygen in the crystal, crystalline perfection is enhanced significantly. However, under heavy chemical reduction, the number of vacancy defects is increased to a significant extent. Raman scattering, dielectric and photoluminescence studies also show interesting features, with excellent correlation with the degree of crystalline perfection influenced by the processes of reduction and poling.

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Modulation of quartz-like GeO2structure by Si substitution: an X-ray diffraction study of Ge1−xSixO2(0 ≤x< 0.2) flux-grown single crystals

Journal of Applied Crystallography ◽

10.1107/s0021889812003081 ◽

2012 ◽

Vol 45 (2) ◽

pp. 272-278 ◽

Cited By ~ 16

Author(s):

Adrien Lignie ◽

Dominique Granier ◽

Pascale Armand ◽

Julien Haines ◽

Philippe Papet

Keyword(s):

Single Crystals ◽

Room Temperature ◽

Piezoelectric Materials ◽

Structural Parameters ◽

X Ray Diffraction ◽

X Ray ◽

Spontaneous Nucleation ◽

Tetrahedral Angle ◽

Hydroxy Groups

The spontaneous nucleation by the high-temperature flux method of GeO2and SiO2-substituted GeO2(Ge1−xSixO2) compounds was improved to give single crystals free of hydroxy groups. The crystal structure and quality of these α-quartz-like piezoelectric materials were studied by single-crystal X-ray diffraction at room temperature. The refinements gave excellent final reliability factors, which are an indication of single crystals with a low level of defects. A good correlation was found between the silicon content in Ge1−xSixO2crystals determined through extrapolation from the inter-tetrahedral bridging angle and that found from energy-dispersive X-ray spectroscopy. The effect of germanium replacement by silicon on the distortion of the α-quartz-type GeO2structure was followed by the evolution of the intra-tetrahedral angle and other structural parameters. TheTO4(T= Si, Ge) distortion was found to be larger in α-GeO2than in α-SiO2and, as expected, the irregularity of theTO4tetrahedra decreased linearly as the substitution of Si for Ge increased.

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Effect of trytophan as dopant on potassium acid phthalate single crystals

10.31221/osf.io/cn28k ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Single Crystals ◽

Room Temperature ◽

Visible Region ◽

X Ray Diffraction ◽

X Ray ◽

Slow Evaporation Technique ◽

Absorption Studies ◽

Evaporation Technique ◽

Potassium Acid Phthalate ◽

Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

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Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

International Journal of PIXE ◽

10.1142/s0129083597000308 ◽

1997 ◽

Vol 07 (03n04) ◽

pp. 265-275

Author(s):

R. Q. Zhang ◽

S. Yamamoto ◽

Z. N. Dai ◽

K. Narumi ◽

A. Miyashita ◽

...

Keyword(s):

Single Crystals ◽

Ion Beam ◽

Pressure Control ◽

Floating Zone ◽

X Ray Diffraction ◽

X Ray ◽

Beam Analysis ◽

Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

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D-19 Combining 2D and Point Detectors for Rapid and High-Resolution High-Energy X-ray Diffraction of Powders and Single Crystals in Multiple Sample Environments

Powder Diffraction ◽

10.1154/1.2754515 ◽

2007 ◽

Vol 22 (2) ◽

pp. 189-189

Author(s):

Y. Ren

Keyword(s):

High Resolution ◽

Single Crystals ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Multiple Sample

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Analysis of Electronic Properties from Magnetotransport Measurements on Ba(Fe1−xNix)2As2 Thin Films

Materials ◽

10.3390/ma13030630 ◽

2020 ◽

Vol 13 (3) ◽

pp. 630

Author(s):

Ilya Shipulin ◽

Stefan Richter ◽

Aleena Anna Thomas ◽

Kornelius Nielsch ◽

Ruben Hühne ◽

...

Keyword(s):

Single Crystals ◽

Measurement Data ◽

X Ray Diffraction ◽

Crystalline Perfection ◽

Ni Doping ◽

Ginzburg Landau ◽

Electronic Parameters ◽

Electronic Heat ◽

Good Agreement

We performed a detailed structural, magnetotransport, and superconducting analysis of thin epitaxial Ba(Fe1−xNix)2As2 films with Ni doping of x = 0.05 and 0.08, as prepared by pulsed laser deposition. X-ray diffraction studies demonstrate the high crystalline perfection of the films, which have a similar quality to single crystals. Furthermore, magnetotransport measurements of the films were performed in magnetic fields up to 9 T. The results we used to estimate the density of electronic states at the Fermi level, the coefficient of electronic heat capacity, and other electronic parameters for this compound, in their dependence on the dopant concentration within the framework of the Ginzburg–Landau–Abrikosov–Gorkov theory. The comparison of the determined parameters with measurement data on comparable Ba(Fe1−xNix)2As2 single crystals shows good agreement, which confirms the high quality of the obtained films.

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