Vibrational properties of BaFe11.1Sc0.9O19 hexaferrite at high and low temperatures

2020 ◽  
Vol 34 (33) ◽  
pp. 2050381
Author(s):  
A. I. Mammadov ◽  
N.T. Dang ◽  
R. Z. Mehdiyeva ◽  
À. V. Trukhanov ◽  
R. E. Huseynov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperatures ◽  
Low Temperatures ◽  
Structural Phase ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Powder Samples ◽  
Raman Modes ◽  
High And Low Temperatures

[Formula: see text] hexaferrite compound was synthesized, the crystal structure was studied by the X-ray diffraction method. Powder samples were prepared from the mark “analytical grade” oxides [Formula: see text], [Formula: see text] and carbonate BaCO3. It was found that under normal conditions and at room temperatures, the crystal structure of this compound has hexagonal symmetry with the P63mmc space group. The lattice parameters correspond to the values: [Formula: see text] and [Formula: see text]. Atomic dynamics of [Formula: see text] hexaferrite in the range of low temperatures of [Formula: see text] and high temperatures of [Formula: see text] were studied. As a result of the analysis of the spectra obtained by the Raman spectroscopy method, it was determined that the structural phase transition does not occur in this compound over a wide temperature range [Formula: see text]. At the room temperature, the obtained Raman modes are observed at both low and high temperatures.

scholarly journals XRD, DTA AND TGA INVESTIGATIONS OF THE BaFe12-xAlxO19 SOLID SOLITIONS

2014 ◽  
Vol 10 (5) ◽  
pp. 2669-2673 ◽  
Author(s):  
Sakin Jabarov ◽  
Alex Trukhanov ◽  
Sergey Trukhanov ◽  
Ali Mammadov ◽  
Vitaly Turchenko ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Phase ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Ion Radius ◽  
Dta Curve

By X-ray diffraction, differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) were investigated BaFe12-xAlxO19 hexaferrites with various concentrations of Al (x = 0.3, 0.9 and 1.2). Crystal structure of compounds was determined, and it determined that under normal condition (P = 0 GPa, T = 300 K) they possess structure is hexagonal symmetry with the space group P63/mmc. Replacing Fe3+ ions Al3+ with ions, on account of reducing ion radius, decrease of indices of parameters was occurred. This crystal structure is saved in a temperature range 30 - 950 ºC and structural phase transition do not occur. Energy supplied to a system is fully swallowed by a system, monotonic decrease is occurred in TGA curve and in DTA curve endo and exo effects do not occur.

A New X‐Ray Diffraction Method for Studying Imperfections of Crystal Structure in Polycrystalline Specimens

1951 ◽  
Vol 22 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Alfred J. Reis ◽  
Jerome J. Slade ◽  
Sigmund Weissmann
Keyword(s):  
Crystal Structure ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

The Synthesis of Ce-Filled CoSb3 and Characterization of its Magnetic and Structural Properties

2003 ◽  
Vol 793 ◽  
Author(s):  
Arwyn L. E. Smalley ◽  
Brandon Howe ◽  
David C. Johnson
Keyword(s):  
Low Temperatures ◽  
Magnetic Measurements ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Ferromagnetic Component ◽  
Phase Pure ◽  
Powder Samples

ABSTRACTA series of cerium-containing CoSb3 samples were synthesized, with cerium quantities varying from 0 to 2 stoichiometric equivalents. These samples were annealed at low temperatures to crystallize the kinetically stable phases CexCo4Sb12 (x = 0–0.5). X-ray diffraction showed that these samples were phase pure, and Rietveld analysis on x-ray diffraction data from powder samples indicated that these samples were 25–88% crystalline. Electrical measurements showed that these samples are n-type, which was previously unknown in CexCo4Sb12. Magnetic measurements showed that the samples were paramagnetic due to the cerium being incorporated into the diamagnetic CoSb3 compound. In addition, they contained a ferromagnetic component that was attributed to the amorphous, cerium-containing phase.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

Bildung von Arsensäure aus [As2Cl8]2Ionen und Ozon. Die Kristallstruktur von PPh4Cl · H3AsO4 / Formation of Arsenic Acid from [As2Cl8]2- Ions and Ozone. Crystal Structure of PPh4Cl · H3AsO4

1992 ◽  
Vol 47 (12) ◽  
pp. 1677-1680 ◽  
Author(s):  
Karin Ruhlandt-Senge ◽  
Alfred-Dirk Bacher ◽  
Ulrich Müller
Keyword(s):  
Crystal Structure ◽  
Low Temperatures ◽  
X Ray Diffraction ◽  
Arsenic Acid ◽  
Subsequent Reaction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray

Reaction of ozone with (PPh4)2[As2Cl8] in CH2C12 at low temperatures yields a red compound, possibly an ozonide. Upon evaporation of the solvent at –78 °C the ozone is released again. At -40 °C or above a subsequent reaction yields PPh4[AsCl6], PPh4Cl · H3AsO4, and other products. The crystal structure of PPh4Cl · H3AsO3 was determined by X-ray diffraction (4253 observed reflexions, R = 0.031). It is triclinic, space group P1̅, and consists of H3AsO4 molecules joined to dimer units via H bridges and associated via O–H · · · Cl- bridges to strands. The packing of the PPh4+ ions is discussed. Products of the reaction of (PPh4)2[Sb2Cl8] with ozone in CH2C12 are PPh4[SbCl6] and (PPh4)2[SbOCl4]2 · 2 CH2Cl2.

The Influence of Emulsifiers on the Crystal Properties of Tristearin and Trilaurin

1988 ◽  
Vol 3 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J. Schlichter ◽  
I. Mayer ◽  
S. Sarig ◽  
N. Garti
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Diffraction Method ◽  
The Other ◽  
Sorbitan Monostearate ◽  
X Ray Diffraction ◽  
Sorbitan Monolaurate ◽  
X Ray ◽  
Crystal Properties ◽  
Long Chain

AbstractThe effect of solid emulsifiers, added at the level of 10%, on the lattice parameters of tristearin and trilaurin, has been studied by powder X-ray diffraction method. The presence of sorbitan monostearate and glycerol-l-stearate affects slightly the lattice constant a in tristearin; on the other hand, although sorbitan monostearate causes an increase in a of trilaurin, glycerol-l-stearate does not. The presence of sorbitan monolaurate and glycerol-l-laurate affect a of trilaurin similarly to the long chain emulsifiers.A correlation between the effect on a and the increase in melting point has been found.The presence of the emulsifier does not alter drastically the lattice dimensions of the fat. The slight dissimilarity in crystal structure between tristearin and trilaurin is confirmed by the diverse effects of the emulsifiers on the internal structure of the fat.

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