CRYSTAL STRUCTURE, ELECTRICAL CONDUCTIVITY AND THERMAL EXPANSION OF Pr1-xSrxFeO3-δ(0 ≤ x ≤ 0.6)

2012 ◽  
Vol 26 (32) ◽  
pp. 1250174 ◽  
Author(s):  
V. PRASHANTH KUMAR ◽  
Y. S. REDDY ◽  
P. KISTAIAH ◽  
C. VISHNUVARDHAN REDDY
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Room Temperature ◽  
Small Polaron ◽  
Linear Thermal Expansion ◽  
Lattice Parameter ◽  
Polaron Hopping ◽  
X Ray ◽  
Perovskite Type

The crystal structure at room temperature (RT), thermal expansion from RT to 1000°C and electrical conductivity, from RT to 600°C, of the perovskite-type oxides in the system Pr 1-x Sr x FeO 3(x = 0, 0.2, 0.4, 0.6) were studied. All the compounds have the orthorhombic perovskite GdFeO 3-type structure with space group Pbnm. The lattice parameters were determined by X-ray powder diffraction. The Pseudo cubic lattice parameter decreases with an increase in x, while the coefficient of linear thermal expansion increases. The thermal expansion is almost linear for x = 0 and 0.2. The electrical conductivity increases with increasing x while the activation energy decreases. The electrical conductivity can be described by the small polaron hopping conductivity model.

Confirmation of the new technique for measuring the linear thermal expansion of silicon

1993 ◽  
Vol 8 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Liu Fengchao
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Accurate Determination ◽  
Linear Thermal Expansion ◽  
Linear Expansion Coefficient ◽  
X Ray ◽  
High Purity Silicon ◽  
Different Temperatures ◽  
Better Than

This paper further confirms that the direct measurement of diffraction angles at different temperatures by using the X-ray diffractometer is better than measurement of the lattice parameters for the rapid and accurate determination of the linear thermal expansion of silicon. High purity silicon has the linear expansion coefficient, α= (2.45±0.05) × 10−6/°C at room temperature. This value does not change for doped P-type and N-type silicon.

Controllable Thermal Expansion in In2-xFexMoxO12

2014 ◽  
Vol 602-603 ◽  
pp. 677-680
Author(s):  
Mei Mei Wu ◽  
Yun Tao Liu
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Room Temperature ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Orthorhombic Phase ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Content

The structural and thermal expansion properties of solid solutions In2-xFexMo3O12have been characterized using X-ray diffraction. The lattice parameters decrease linearly with increasing Fe content at room temperature. All compounds exhibit monoclinic structure at room temperature, and transform to orthorhombic phase upon heating. Monoclinic In2-xFexMo3O12(x= 0.3, 1.0 and 1.3) possess strong positive thermal expansion, while the linear thermal expansion coefficient of orthorhombic phase varies from zero/near-zero to positive with increasing Fe3+content.

Synthesis and structural characterization of BaV4O9

2007 ◽  
Vol 63 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Thomas Reeswinkel ◽  
Sebastian Prinz ◽  
Karine M. Sparta ◽  
Georg Roth
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Structural Characterization ◽  
Room Temperature ◽  
Monoclinic Space Group ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Tensor

The new spin ½ V4+ barium oxovanadate BaV4O9 was synthesized and studied by means of single-crystal X-ray diffraction. Its room-temperature structure is monoclinic, space group P2/c. We discuss the temperature evolution of the crystal structure and thermal expansion tensor of the material between 293 and 100 K.

X-ray powder diffraction study of cesium ammonium hexachlorotellurate [Cs0.86(NH4)0.14]2TeCl6

2006 ◽  
Vol 21 (3) ◽  
pp. 225-228 ◽  
Author(s):  
R. Karray ◽  
A. Kabadou ◽  
A. Ben Salah ◽  
A. van der Lee
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Related Compound ◽  
Room Temperature ◽  
Diffraction Method ◽  
Large Family ◽  
Lattice Parameter ◽  
X Ray ◽  
Ammonium Group ◽  
Ir Spectroscopic

The crystal structure of cesium ammonium hexachlorotellurate [Cs0.86(NH4)0.14]2TeCl6, has been determined using X-ray powder diffraction techniques. At room temperature, the title compound crystallizes in the cubic space group Fm3m, with a lattice parameter a=10.470(17) Å. The Rietveld refinement of the structure led to final confidence factors Rp=0.0338 and Rwp=0.0487. The structure of [Cs0.86(NH4)0.14]2TeCl6 belongs to the large family of K2PtCl6-related structures. The H atoms of the ammonium group are orientated with its apex toward Te atoms as seen in the related compound (NH4)2SiF6. An IR spectroscopic study was performed to confirm the results of the diffraction method, notably concerning the presence of the ammonium group.

Crystal Structure of the High-Temperature Phase of a Compound Sr2ZnWO6

1992 ◽  
Vol 7 (4) ◽  
pp. 226-227 ◽  
Author(s):  
Fu Zhengmin ◽  
Li Wenxiu
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Lattice Parameter ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Cubic System ◽  
Measured Density

AbstractThe crystal structure of the high-temperature phase of Sr2ZnWO6 prepared by air quenching from 1200° C has been determined by means of X-ray powder diffraction. β-Sr2ZnWO6 belongs to the cubic system, with space group Fm3m and a lattice parameter a = 7.9266 Å at room temperature. Its measured density is Dm = 6.93g/cm3, and each unit cell contains four formula weights.

scholarly journals Crystal structure, thermal and electrotransport properties of NdBa1–xSrxFeCo0.5Cu0.5O5+δ (0.02 ≤ x ≤ 0.20) solid solutions

2021 ◽  
Vol 8 (3) ◽  
pp. 20218301
Author(s):  
A. I. Klyndyuk ◽  
Ya. Yu. Zhuravleva ◽  
N. N. Gundilovich
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Solid Solutions ◽  
Electrical Transport ◽  
Linear Thermal Expansion ◽  
Solid State Reactions ◽  
Partial Substitution ◽  
Cell Parameters

Using solid-state reactions method, the solid solutions of layered oxygen-deficient perovskites NdBa1–xSrxFeCo0.5Cu0.5O5+δ (0.02 ≤ x ≤ 0.20) were prepared; their crystal structure, thermal stability, thermal expansion, electrical conductivity and thermopower were studied. It was found that NdBa1–xSrxFeCo0.5Cu0.5O5+δ phases crystallize in tetragonal syngony (space group P4/mmm) and are p-type semiconductors, whose conductivity character at high temperatures changed to the metallic one due to evolution from the samples of so-called weakly-bonded oxygen. Partial substitution of barium by strontium in NdBaFeCo0.5Cu0.5O5+δ leads to the small decreasing of unit cell parameters, thermal stability and thermopower of NdBa1–xSrxFeCo0.5Cu0.5O5+δ solid solutions, increasing of their electrical conductivity values and slightly affects their linear thermal expansion coefficient and activation energy of electrical transport values.

scholarly journals X-Ray Analysis of Alpha Mercuric Iodide Crystal Structure and Processing Effects

1993 ◽  
Vol 302 ◽  
Author(s):  
L. Keller ◽  
E.X. Wang ◽  
A.Y. Cheng
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Device Fabrication ◽  
Mercuric Iodide ◽  
Rocking Curve ◽  
X Ray ◽  
Processing Effects ◽  
Crystal Damage ◽  
Iodide Crystal

ABSTRACTX-ray topography and rocking curve experiments were performed on α-mercuric iodide samples. As-grown crystals were examined for intrinsic defects and crystallinity. Orientation of certain defects depends on the direction of crystal growth. The propagation of as-grown crystalline features was documented. The extent of crystal damage introduced during various steps of device fabrication such as sawing, polishing, etching and contact deposition was explored. Coefficients of linear thermal expansion of α33 = 54 ± 5 (10−6/°C) along the tetragonal c-axis, \001] direction and ±ll = 11 ± 4 (10−6/°C) in the \100] direction were measured.

SYNTHESIS, STRUCTURAL AND MAGNETIC PROPERTIES OF DOUBLE PEROVSKITES Sr2CrWO6

2005 ◽  
Vol 19 (01n03) ◽  
pp. 537-540 ◽  
Author(s):  
T. S. CHAN ◽  
R. S. LIU ◽  
C. Y. HUANG
Keyword(s):  
Crystal Structure ◽  
Valence State ◽  
Room Temperature ◽  
Standard Sample ◽  
Double Perovskite ◽  
Lattice Parameter ◽  
Double Perovskites ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
X Ray Absorption

The double perovskite ( Sr 2 CrWO 6) has been prepared in polycrystalline state by solid state reaction. At room temperature, the crystal structure is cubic (space group: Fm3m) with lattice parameter of 7.8200(2) (Å). Both ρ( H =0) and ρ( H =5 T ) show a semiconductor-like behavior over the whole temperature range up to 5 K. The highest MR(magnetoresistance) value of 55% ( H =5 T ) was observed at 25 K. The valence state of Cr was determined by the X-ray absorption spectroscopy at Cr -L edge. The results, compared to the standard sample, show that the valence state of Cr is 3+.

A high-temperature X-ray diffraction study of the NiO–Li2O system

1971 ◽  
Vol 4 (4) ◽  
pp. 293-297 ◽  
Author(s):  
C. J. Toussaint
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Thermal Expansion ◽  
High Temperature ◽  
Transition Temperature ◽  
Diffraction Study ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallographic Study

A crystallographic study of the system Ni2+ 1−2x Ni3+ x Li+ x O has been carried out. The crystal structure of the material in the range 0≤x≤0.4 at room temperature and up to 1000°C has been studied. The principal coefficients of thermal expansion and the phase diagram are given. The structural rhombohedral → face-centred cubic transition temperature of NiO has been determined.

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