Determination of Crystallinity in Li1−xMgxMn2O4 Nanocrystals Based on Diffraction Patterns Correlation Analysis and Strain Mapping

We wish to report in this paper measurements of the inelastic scattering component due to the collective excitations (plasmons) and single particlehole excitations of the valence electrons in Al. Such scattering contributes to the diffuse electronic scattering seen in electron diffraction patterns and has recently been considered of significance in weak-beam images (see Gai and Howie) . A major problem in the determination of such scattering is the proper correction for multiple scattering. We outline here a procedure which we believe suitably deals with such problems and report the observed single scattering spectrum.In principle, one can use the procedure of Misell and Jones—suitably generalized to three dimensions (qx, qy and #x2206;E)--to derive single scattering profiles. However, such a computation becomes prohibitively large if applied in a brute force fashion since the quasi-elastic scattering (and associated multiple electronic scattering) extends to much larger angles than the multiple electronic scattering on its own.

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STEM and ELS Observation of Early Oxide Formation on the Surface of Cr Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001768 ◽

1980 ◽

Vol 38 ◽

pp. 412-413

Author(s):

Fumio Watari ◽

J. M. Cowley

Keyword(s):

Thin Films ◽

Optical System ◽

Room Temperature ◽

Oxide Formation ◽

Initial Nucleation ◽

Diffraction Patterns ◽

Relationship Of ◽

Multiple Twinning ◽

Moderately High Temperature

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.

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Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽

10.3390/cryst11020129 ◽

2021 ◽

Vol 11 (2) ◽

pp. 129

Author(s):

Liana Vella-Zarb ◽

Ulrich Baisch

Keyword(s):

Variable Temperature ◽

Chemical Properties ◽

Crystal Form ◽

X Ray Diffraction ◽

Crystal Forms ◽

X Ray ◽

Physical Chemical ◽

Diffraction Patterns ◽

Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

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Determining the energy-dependent X-ray flux variation of a synchrotron beamline using Laue diffraction patterns

Journal of Applied Crystallography ◽

10.1107/s0021889810052015 ◽

2011 ◽

Vol 44 (1) ◽

pp. 177-183 ◽

Cited By ~ 7

Author(s):

Catherine Dejoie ◽

Martin Kunz ◽

Nobumichi Tamura ◽

Colin Bousige ◽

Kai Chen ◽

...

Keyword(s):

Incident Energy ◽

Flux Variation ◽

Laue Diffraction ◽

X Ray ◽

Measured Flux ◽

Highly Sensitive ◽

Diffraction Patterns ◽

Energy Dependent ◽

Flux Curve

Although the spectrum originating from a superconducting bending magnet is quasi-continuous, it shows important intensity variations through its spectral range. A method to determine the incident energy-dependent flux variation based on the comparison between observed intensities and the calculated intensities of a well known structure (calcite) is presented here. It is found that the measured flux is highly sensitive to the use of correct Debye–Waller factors for the atoms of the standard crystal. By using the measured flux curve, it was possible to unambiguously index the Laue diffraction pattern of a trigonal crystal structure in its hexagonal setting. This is a crucial but difficult first step for the determination of strain and stress in materials with this symmetry, such as quartz, Mg, Ti, Znetc.

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Determination of hydrogen ordering within the β-RH2+xphase (R= Ho, Y) using electron diffraction techniques

Journal of Applied Crystallography ◽

10.1107/s0021889800009523 ◽

2000 ◽

Vol 33 (5) ◽

pp. 1246-1252 ◽

Cited By ~ 3

Author(s):

Elizabeth J. Grier ◽

Amanda K. Petford-Long ◽

Roger C. C. Ward

Keyword(s):

Electron Diffraction ◽

Neutron Scattering ◽

Diffraction Pattern ◽

Computer Simulations ◽

Fluorite Structure ◽

Long Range Order ◽

Hydrogen Atoms ◽

Ordered Structures ◽

Diffraction Patterns

Computer simulations of the electron diffraction patterns along the [\bar{1}10] zone axes of four ordered structures within the β-RH2+xphase, withR= Ho or Y, and 0 ≤x≤ 0.25, have been performed to establish whether or not the hydrogen ordering could be detected using electron diffraction techniques. Ordered structures within otherRH2+x(R= Ce, Tb) systems have been characterized with neutron scattering experiments; however, for HoH(D)2+x, neutron scattering failed to characterize the superstructure, possibly because of the lowxconcentration or lack of long-range order within the crystal. This paper aims to show that electron diffraction could overcome both of these problems. The structures considered were the stoichiometric face-centred cubic (f.c.c.) fluorite structure (x= 0), theD1 structure (x= 0.125), theD1astructure (x= 0.2) and theD022structure (x= 0.25). In the stoichiometric structure, with all hydrogen atoms located on the tetrahedral (t) sites, only the diffraction pattern from the f.c.c. metal lattice was seen; however, for the superstoichiometric structures, with the excess hydrogen atoms ordered on the octahedral (o) sites, extra reflections were visible. All the superstoichiometric structures showed extra reflections at the (001)f.c.c.and (110)f.c.c.type positions, with structureD1 also showing extra peaks at (½ ½ ½)f.c.c.. These reflections are not seen in the simulations at similar hydrogen concentrations with the hydrogen atoms randomly occupying theovacancies.

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Determination of sample surface topography using electron back-scatter diffraction patterns

Scripta Materialia ◽

10.1016/j.scriptamat.2016.03.032 ◽

2016 ◽

Vol 120 ◽

pp. 23-26 ◽

Cited By ~ 4

Author(s):

M. Chapman ◽

P.G. Callahan ◽

M. De Graef

Keyword(s):

Surface Topography ◽

Sample Surface ◽

Electron Back Scatter Diffraction ◽

Diffraction Patterns

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First Experimental Determination of an Adsorption Site Using Multiple Wave Number Photoelectron Diffraction Patterns

Physical Review Letters ◽

10.1103/physrevlett.73.3548 ◽

1994 ◽

Vol 73 (26) ◽

pp. 3548-3551 ◽

Cited By ~ 24

Author(s):

M. Zharnikov ◽

M. Weinelt ◽

P. Zebisch ◽

M. Stichler ◽

H. -P. Steinrück

Keyword(s):

Experimental Determination ◽

Adsorption Site ◽

Wave Number ◽

Multiple Wave ◽

Photoelectron Diffraction ◽

Diffraction Patterns

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Disordered materials studied using neutron polarization analysis on the multi-detector spectrometer, D7

Journal of Applied Crystallography ◽

10.1107/s0021889808039162 ◽

2008 ◽

Vol 42 (1) ◽

pp. 69-84 ◽

Cited By ~ 104

Author(s):

J. R. Stewart ◽

P. P. Deen ◽

K. H. Andersen ◽

H. Schober ◽

J.-F. Barthélémy ◽

...

Keyword(s):

Cross Sections ◽

Disordered Systems ◽

Disordered Materials ◽

Polarization Analysis ◽

Neutron Spectrometer ◽

Neutron Polarization ◽

Unambiguous Determination ◽

Diffraction Patterns ◽

Scattering Cross Sections

The technique of longitudinal neutron polarization analysis on a multi-detector neutron spectrometer (so-called `xyz'-polarization analysis) is presented. This technique allows the simultaneous and unambiguous determination of the nuclear, magnetic and nuclear spin-incoherent scattering cross sections as a function of both momentum transfer and energy transfer. The implementation ofxyz-polarization analysis on the recently upgraded D7 spectrometer at the Institut Laue–Langevin in Grenoble is described. Several examples of neutron polarization analysis studies of disordered systems on D7 are given, illustrating the valuable information which can be retrieved from the analysis of neutron diffraction patterns between the Bragg peaks.

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On the Characterisatiopn of Order-Disorder in Ion-Irradiated Pyrochlore Compounds by Electron Scattering Methods

MRS Proceedings ◽

10.1557/proc-1122-o09-03 ◽

2008 ◽

Vol 1122 ◽

Author(s):

Gregory R. Lumpkin ◽

Karl R. Whittle ◽

Mark G. Blackford ◽

Katherine L. Smith ◽

Nestor J. Zaluzec

Keyword(s):

Electron Scattering ◽

Diffuse Scattering ◽

Zone Axis ◽

Irradiation Damage ◽

Nuclear Materials ◽

Crystalline Fraction ◽

Selected Area Electron Diffraction ◽

Pyrochlore Compounds ◽

Diffraction Patterns

AbstractSelected area electron diffraction patterns are routinely used to determine the effects of irradiation damage in nuclear materials. Using zone axis orientations, the intensities of Bragg beams change from a dynamical to kinematic-like state due to the presence of amorphous domains in the material. Such changes in beam intensities, together with the increased diffuse scattering from the increasing amorphous fraction, present a major obstacle to the determination of cation or anion disorder in the crystalline fraction.

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UPLC-MS/MS Determination of Linezolid and Heme in Plasma of Infected Patients and Correlation Analysis

BioMed Research International ◽

10.1155/2021/6679076 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Yingying Wang ◽

Xuemei Ye ◽

Qin Lan ◽

Xiaofang Ke ◽

Lufeng Hu ◽

...

Keyword(s):

Correlation Analysis ◽

Healthy Subjects ◽

Haematological Toxicity ◽

Diagnostic Value ◽

High Concentration ◽

High Positive Correlation ◽

Positive Correlation ◽

Early Diagnose ◽

The Relationship

Linezolid can cause serious haematological toxicity, such as thrombocytopenia and aneamia. Heme, composed of iron and porphyrin, is an important component of hemoglobin. In order to investigate the relationship between the concentration of linezolid and heme in the plasma of infected patients, a UPLC-MS/MS method that can determine the concentrations of linezolid and heme simultaneously was developed and validated. A total of 96 healthy subjects and 81 infected patients, who received blood routine blood tests, were included and determined by the UPLC-MS/MS method. The results showed that the concentration of linezolid was 5.08 ± 3.46 μ g / mL in infected patients who were treated with linezolid. The heme in healthy subjects was 7.05 ± 8.68 μ g / mL , and it was significantly decreased to 0.88 ± 0.79 μ g / mL in infected patients ( P < 0.01 ). Spearman correlation analysis showed that linezolid had a high negative correlation with platelet (PLT) ( R = − 0.309 ). Heme had a high positive correlation with hemoglobin (Hb) ( R = 0.249 ) in healthy subjects and infected patients. The ROC analysis showed that heme had diagnostic value to distinguish low Hb (110 g/L). In conclusion, there was a positive correlation between heme and Hb, and this correlation was also observed in infected patients. A high concentration of linezolid was inclined to decrease PLT. Monitoring of heme and linezolid helps in the early diagnose of low Hb and PLT.

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