Simultaneous Synthesis and Consolidation of Nanostructured MoSi2

A new process combining electric field activation and the imposition of pressure from mechanically activated powder mixtures is demonstrated as a means to simultaneously synthesize and densify nano-MoSi2 in one step. Nanophase reactants (Mo + 2Si) produced by mechanical activation are reacted by field activation with the simultaneous application of a uniaxial pressure. Mo + 2Si powders were comilled in a specially designed planetary mill to obtain nanometric reactants but to avoid formation of any product phases. These were then subjected to high alternating currents (1600 A) and pressures of 106 MPa. Under these conditions, a reaction is initiated and completed within a short period of time (3–6 min). The relative density of the product ranged from 82 to 93%. The crystallite size of the MoSi2 compound was determined by x-ray diffraction line-broadening analysis using the Langford method. The size ranged from 58 to 75 nm.

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Interfacial properties of GaSb/InAs superlattices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149969 ◽

1993 ◽

Vol 51 ◽

pp. 826-827

Author(s):

M. E. Twigg ◽

B. R. Bennett ◽

J. R. Waterman ◽

J. L. Davis ◽

B. V. Shanabrook ◽

...

Keyword(s):

Gaas Substrate ◽

Molecular Beam ◽

Infrared Detector ◽

Interfacial Properties ◽

Ex Situ ◽

X Ray Diffraction ◽

Absorption Coefficients ◽

X Ray ◽

Short Period ◽

High Optical Absorption

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.

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A Versatile Approach to Access Trimetallic Complexes Based on Trisphosphinite Ligands

Molecules ◽

10.3390/molecules25030593 ◽

2020 ◽

Vol 25 (3) ◽

pp. 593

Author(s):

Juan Miranda-Pizarro ◽

Macarena G. Alférez ◽

M. Dolores Fernández-Martínez ◽

Eleuterio Álvarez ◽

Celia Maya ◽

...

Keyword(s):

Coordination Chemistry ◽

Late Transition Metal ◽

X Ray Diffraction ◽

X Ray ◽

Full Characterization ◽

Metal Precursors ◽

Straightforward Method ◽

One Step ◽

Late Transition

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.

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Temperature-induced structural phase transitions in RERhSn (RE = Y, Gd-Tm, Lu)

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2021-2008 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Simon Engelbert ◽

Rolf-Dieter Hoffmann ◽

Jutta Kösters ◽

Steffen Klenner ◽

Rainer Pöttgen

Keyword(s):

Rare Earth ◽

Phase Transitions ◽

Driving Force ◽

Room Temperature ◽

Structural Phase ◽

Structural Phase Transitions ◽

Line Broadening ◽

X Ray Diffraction ◽

Temperature Dependent ◽

X Ray

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

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Mechanochemical Preparation of Slow Release Fertilizer Based on Glauconite–Urea Complexes

Minerals ◽

10.3390/min9090507 ◽

2019 ◽

Vol 9 (9) ◽

pp. 507 ◽

Cited By ~ 2

Author(s):

Maxim Rudmin ◽

Elshan Abdullayev ◽

Alexey Ruban ◽

Ales Buyakov ◽

Bulat Soktoev

Keyword(s):

Milling Time ◽

Slow Release ◽

Mechanochemical Activation ◽

Structural Characteristics ◽

Fluorescence Analysis ◽

Planetary Mill ◽

X Ray Diffraction ◽

Mechanochemical Method ◽

X Ray ◽

Slow Release Fertilizers

We investigated the mechanochemical synthesis of complex slow release fertilizers (SRF) derived from glauconite. We studied the effectiveness of the mechanical intercalation of urea into glauconite using planetary and ring mills. The potassium-nitric complex SRFs were synthesized via a mechanochemical method mixing glauconite with urea in a 3:1 ratio. The obtained composites were analyzed using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence analysis, and infrared spectroscopy. The results show that as duration of mechanochemical activation increases, the mineralogical, chemical, and structural characteristics of composites change. Essential modifications associated with a decrease in absorbed urea and the formation of microcrystallites were observed when the planetary milling time increased from 5 to 10 min and the ring milling from 15 to 30 min. Complete intercalation of urea into glauconite was achieved by 20 min grinding in a planetary mill or 60 min in a ring mill. Urea intercalation in glauconite occurs much faster when using a planetary mill compared to a ring mill.

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X-Ray Diffraction Study of Hep Metals. I. Line Broadening in Polycrystalline Cd Powder

Zeitschrift für Naturforschung A ◽

10.1515/zna-1974-1211 ◽

1974 ◽

Vol 29 (12) ◽

pp. 1771-1777 ◽

Cited By ~ 3

Author(s):

N. C. Haider ◽

S. H. Hunter

Keyword(s):

Room Temperature ◽

Small Deformation ◽

Correction Factors ◽

Line Broadening ◽

X Ray Diffraction ◽

Fault Probability ◽

Large Particle Size ◽

X Ray ◽

Melting Temperatures ◽

Diffraction Patterns

Powder Cd of 99.999% purity was prepared at room temperature (25 °C) and x-ray diffraction patterns were obtained using CuKaα radiation with Ni-filter. The line broadening was analyzed after incorporating the appropriate correction factors. At room temperature Cd was found to have large particle size (653 A), small root mean square strain (.001), small deformation fault probability a (.003). and negligible growth fault probability β(0). Compared to other hep metals which have been studied earlier and which have higher melting temperatures, metal Cd is much less affected by mechanical deformation at room temperature.

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Investigation of Residual Strains of the Second Kind in Plastically Deformed Metallic Materials

MRS Proceedings ◽

10.1557/proc-376-409 ◽

1994 ◽

Vol 376 ◽

Cited By ~ 2

Author(s):

M. Vrána ◽

P. Klimanek ◽

T. Kschidock ◽

P. Lukáš ◽

P. Mikula

Keyword(s):

High Resolution ◽

Neutron Diffraction ◽

Stacking Faults ◽

Metallic Materials ◽

Line Broadening ◽

X Ray Diffraction ◽

X Ray ◽

Neutron Diffractometer ◽

Residual Strains ◽

Good Agreement

ABSTRACTInvestigation of strongly distorted crystal structures caused by dislocations, stacking-faults etc. in both plastically deformed f.c.c. and b.c.c. metallic materials was performed by the analysis of the neutron diffraction line broadening. Measurements were realized by means of the high resolution triple-axis neutron diffractometer equipped by bent Si perfect crystals as monochromator and analyzer at the NPI Řež. The substructure parameters obtained in this manner are in good agreement with the results of X-ray diffraction analysis.

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Effect of the BSCCO superconducting properties by tiny Y2O3 addition

Modern Physics Letters B ◽

10.1142/s0217984916503280 ◽

2016 ◽

Vol 30 (26) ◽

pp. 1650328

Author(s):

Yan Dong ◽

Aimin Sun ◽

Bin Xu ◽

Hongtao Zhang ◽

Meng Zhang

Keyword(s):

Volume Fraction ◽

Superconducting Properties ◽

X Ray Diffraction ◽

Critical Transition Temperature ◽

Solid State Reaction Technique ◽

X Ray ◽

Oxide Addition ◽

One Step ◽

Step Transition ◽

Y2o3 Addition

In this paper, the effect of tiny Y2O3 addition in (Bi,[Formula: see text]Pb)-2223 superconductor prepared by solid state reaction technique was studied. The properties of samples have been investigated via X-ray diffraction (XRD), resistance–temperature ([Formula: see text]–[Formula: see text]) curve, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). XRD data indicated that all samples are multiphase and the major phases are high-temperature phases and low-temperature phases. The volume fraction of (Bi,[Formula: see text]Pb)-2223 is not great change with tiny Y2O3 addition. All samples exhibit superconducting phase with the critical transition temperature and one-step transition, however, the transition width was decreased with the Y2O3 addition up to 0.04 wt.% and sharp increased with the excessive oxide addition. SEM pictures show that the Y2O3 appeared on the flake-type grains surface obviously, but the number and size of the hole between grains are decreased in the 0.04 wt.% addition.

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One Step Synthesis and Characterization of Zirconia-Graphene Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.600.174 ◽

2012 ◽

Vol 600 ◽

pp. 174-177 ◽

Cited By ~ 1

Author(s):

Jian Fei Xia ◽

Zong Hua Wang ◽

Yan Zhi Xia ◽

Fei Fei Zhang ◽

Fu Qiang Zhu ◽

...

Keyword(s):

Synthesis And Characterization ◽

Two Dimensional ◽

X Ray Diffraction ◽

X Ray ◽

Graphene Composite ◽

Transmission Electron ◽

One Step ◽

Ft Ir ◽

Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

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The Use of the Pseudo-Voigt Function in the Variance Method of X-ray Line-Broadening Analysis

Journal of Applied Crystallography ◽

10.1107/s0021889896015464 ◽

1997 ◽

Vol 30 (4) ◽

pp. 427-430 ◽

Cited By ~ 101

Author(s):

F. Sánchez-Bajo ◽

F. L. Cumbrera

Keyword(s):

Crystallite Size ◽

Original Form ◽

Line Broadening ◽

X Ray Diffraction ◽

Stabilized Zirconia ◽

X Ray ◽

Variance Method ◽

The Mean ◽

Voigt Function

A modified application of the variance method, using the pseudo-Voigt function as a good approximation to the X-ray diffraction profiles, is proposed in order to obtain microstructural quantities such as the mean crystallite size and root-mean-square (r.m.s.) strain. Whereas the variance method in its original form is applicable only to well separated reflections, this technique can be employed in the cases where there is line-profile overlap. Determination of the mean crystallite size and r.m.s. strain for several crystallographic directions in a nanocrystalline cubic sample of 9-YSZ (yttria-stabilized zirconia) has been performed by means of this procedure.

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