Rhombohedral-cubic phase transition characterization of (Pb,Ge)Te using high-temperature XRD

2008 ◽  
Vol 23 (2) ◽  
pp. 137-140 ◽  
Author(s):  
J. Sariel ◽  
I. Dahan ◽  
Y. Gelbstein
Keyword(s):  
High Temperature ◽  
Cylindrical Specimen ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Continuous Transformation ◽  
X Ray ◽  
High Temperature Xrd ◽  
Powder Samples ◽  
Powder Metallurgy Approach

Rhombohedral-cubic transformation in Bi2Te3 doped-Pb1−xGexTe alloys is presented. Samples of Bi2Te3 doped Pb1−xGexTe were prepared by powder metallurgy approach. These powder samples were examined by high-temperature X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy. A bulk (pressed powder) cylindrical specimen was used for dilatometery characterizations. According to the XRD examinations it seems that upon increasing the temperatures a continuous transformation occurs from the rhombohedral to the cubic phase, accompanied by the formation of a small amount of the phase Ge0.74Pb3.26Te4.

scholarly journals Monitoring of FES2 reactions using high-temperature XRD coupled with gas chromatography

2019 ◽  
Vol 34 (2) ◽  
pp. 90-96
Author(s):  
K.-A. M. Stirrup ◽  
M. A. Rodriguez ◽  
E. N. Coker ◽  
J. J. M. Griego ◽  
T. M. Anderson
Keyword(s):  
Gas Chromatography ◽  
High Temperature ◽  
Simultaneous Thermal Analysis ◽  
Gas Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Disulfide ◽  
Thermal Batteries ◽  
High Temperature Xrd

High-temperature X-ray diffraction with concurrent gas chromatography (GC) was employed in the study of iron disulfide (FeS2) cathode pellets disassembled from thermal batteries. When FeS2 cathode materials were analyzed in an air environment, reaction of the KCl and LiCl salt phases led to the formation of Li2(SO4) and KFe2S3 phases beginning at ~230 °C. These phases subsequently reacted to generate various forms of potassium iron sulfates in the 280–500 °C range, with the final products resulting in a β-Fe2O3 phase and K2(SO4). Independent simultaneous thermal analysis coupled with mass spectroscopy (MS) augmented the diffraction results and supported the overall picture of FeS2 decomposition. Both gas analysis measurements (i.e. GC and MS) from the independent experiments confirmed the formation of SO2 off-gas species during the breakdown of the FeS2. In contrast, characterization of the same cathode material under inert conditions showed the persistence of the initial FeS2 phase throughout the entire temperature range of analysis.

scholarly journals High-pressure synthesis and characterization of the non-centrosymmetric scandium borate ScB6O9(OH)3

2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Structure Solution ◽  
Temperature Experiment ◽  
Pressure Synthesis

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.

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.

High pressure growth and characterization of SrCrO3 single crystal

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542025 ◽  
Author(s):  
L. P. Cao ◽  
L. Q. Pan ◽  
W. M. Li ◽  
X. C. Wang ◽  
Q. Q. Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Perovskite Structure ◽  
Resistivity Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Results

Single crystal [Formula: see text] was prepared under high pressure and high temperature. Single crystal X-ray diffraction (XRD) result shows a cubic perovskite structure. The magnetic and resistivity measurement results indicate that [Formula: see text] is a paramagnetic semiconductor.

scholarly journals In situ characterization of the effects of Nb and Sn on the anatase–rutile transition in TiO2 nanotubes using high-temperature X-ray diffraction

2014 ◽  
Vol 307 ◽  
pp. 372-381 ◽  
Author(s):  
Nathália C. Verissimo ◽  
Alessandra Cremasco ◽  
Christiane A. Rodrigues ◽  
Rodnei Bertazzoli ◽  
Rubens Caram
Keyword(s):  
High Temperature ◽  
Tio2 Nanotubes ◽  
X Ray Diffraction ◽  
In Situ Characterization ◽  
X Ray

Synthesis and structural characterization of Li3Y(BO3)2

2017 ◽  
Vol 72 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Boric Acid ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Lithium Carbonate ◽  
X Ray Diffraction ◽  
X Ray

AbstractLi3Y(BO3)2 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes monoclinically in the space group P21/c (no. 14) (Z=4) isotypically to Li3Gd(BO3)2. The structure was refined from single-crystal X-ray diffraction data: a=8.616(3), b=6.416(3), c=10.014(2) Å, β=116.6(2)°, V=494.9(3) Å3, R1=0.0211, and wR2=0.0378 for all data. The crystal structure of Li3Y(BO3)2 consists of [Y2O14] dinuclear units, which are interconnected to each other by planar B(1)O3 groups and LiO4 tetrahedra via common edges and corners along the a axis.

scholarly journals X-Ray Diffraction Study of Oxygen-Conducting Compounds Ln2Mo2O9(Ln = La, Pr)

2014 ◽  
Vol 70 (a1) ◽  
pp. C48-C48
Author(s):  
Alexander Antipin ◽  
Olga Alekseeva ◽  
Natalya Sorokina ◽  
Alexandra Kuskova ◽  
Michail Presniakov ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Basic Research ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Oxide Systems ◽  
Transmission Microscopy ◽  
X Ray ◽  
Oxygen Conductivity ◽  
Oxygen Atoms

Lanthanum molibdate La2Mo2O9(LM) and the compounds on its basis (LAMOX) attract much attention because of the high oxygen conductivity (6x10-2Sm/cm), which were found by Lacorre group. LM has the first-order phase transition at about 5800C and two phases: low-temperature monoclinic α-phase (P21) and high-temperature β-phase (P213) [1]. In the present work single crystals Ln2Mo2O9(Ln = La, Pr) were obtained by spontaneous flux crystallization in the Ln2O3–MoO3oxide systems. The LM and PM single crystals are studied by precision X-ray diffraction and high-resolution transmission microscopy. A cubic cell with a = 7.155(1) and 7.155(1) Å was chosen for two LM samples (LM_I and LM_II, respectively). More than 90% (LM_I) and 60% (LM_II) of the reflections measured were indexed in this cell. The unit cell parameter of the PM compound is slightly shorter: a = 7.087(1) and 7.089(1) Å for the PM_I and PM_II samples, respectively. More than 90% of the reflections measured were indexed for both PM crystals. It was found that the LM_II crystal consists of two cubic components grown together; a ≍ 7.155 Å for both components. The crystal structures for two LM and two PM samples are determined in space group P213. It is found that La and Pr atoms, as well as Mo1 and O1 atoms, are located in the vicinity of 3-fold axes rather than on the axes like in the high-temperature cubic phase. In both structures, the O2 and O3 positions are partially occupied. The coexistence of different configurations of the Mo coordination environment facilitates the oxygen ion migration in the structure. Based on the X-ray data, activation energies of oxygen atoms are calculated and migration paths of oxygen ions in the structures are analyzed. The conductivity of PM crystals is close to that of LM crystals. Oxygen atoms O2 and O3 make main contributions to ion conductivity of LM and PM. This study was supported in part by part by the Russian Foundation for Basic Research (project no. 14-02-00531).

Preparation and characterization of a novel solid solution of aluminum in tungsten carbide by mechanically activated high-temperature reaction

2006 ◽  
Vol 21 (7) ◽  
pp. 1700-1703 ◽  
Author(s):  
Junmin Yan ◽  
Xianfeng Ma ◽  
Wei Zhao ◽  
Huaguo Tang ◽  
Changjun Zhu ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Substitutional Solid Solution ◽  
Phase Identification ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
High Temperature Reaction

In this work, a novel substitutional solid solution (W0.8Al0.2)C was synthesized by mechanically activated high-temperature reaction. X-ray diffraction was used for phase identification during the whole reaction process. Environment scanning electronic microscopy–field emission gun and energy dispersive x-ray were used to investigate the microstructure and the quantitative material composition of the specimen. (W0.8Al0.2)C was found to crystallize in the WC-type, and the cell parameters were a = 2.907(1) Å and c = 2.837(1) Å. The hardness of (W0.8Al0.2)C was tested to be 19.3 ± 1 GPa, and the density was 13.19 ± 0.05 g cm−3.

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