scholarly journals Crystal structure, thermal expansion and electrical conduction behavior of PrNi1−xFexO3−δ at high temperature

2017 ◽  
Vol 125 (4) ◽  
pp. 227-235 ◽  
Author(s):  
Kazuhiro KURATA ◽  
Yuichiro TOYOTA ◽  
Tsubasa SATO ◽  
Eiki NIWA ◽  
Katusmi SHOZUGAWA ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
High Temperature ◽  
Electrical Conduction ◽  
Conduction Behavior

A high temperature structural phase transition in crocoite (PbCrO4) at 1068 K: crystal structure refinement at 1073 K and thermal expansion tensor determination at 1000 K

2000 ◽  
Vol 64 (2) ◽  
pp. 291-300 ◽  
Author(s):  
K. S. Knight
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Thermal Expansion ◽  
High Temperature ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Structure Type ◽  
Temperature Phase ◽  
Thermal Expansion Tensor ◽  
Principal Axes

AbstractHigh-resolution, neutron time-of-flight, powder diffraction data have been collected on natural crocoite between 873 and 1073 K. Thermal analysis carried out in the 1920s had suggested that chemically pure PbCrO4 exhibited two structural phase transitions, at 964 K, to the β phase, and at 1056 K, to the γ phase. In this study, no evidence was found for the α-β structural phase transition, however a high-temperature phase transition was found at ∼1068 K from the ambient-temperature monazite structure type to the baryte structure type. The phase transition, close to the temperatures reported for the β to γ phase modifications, is first order and is accompanied by a change in volume of −1.6%. The crystal structure of this phase has been refined using the Rietveld method to agreement factors of Rp = 0.018, Rwp = 0.019, Rp = 0.011. No evidence for premonitory behaviour was found in the temperature dependence of the monoclinic lattice constants rom 873 K to 1063 K and these have been used to determine the thermal expansion tensor of crocoite just below the phase transition. At 1000 K the magnitudes of the tensor coefficients are α11, 2.66(1) × 10−5 K−1; α22, 2.04(1) × 10−5 K−1; α33, 4.67(4) × 10−5 K−1; and α13, −1.80(2) × 10−5 K−1 using the IRE convention for the orientation of the tensor basis. The orientation of the principal axes of the thermal expansion tensor are very close to those reported previously for the temperature range 50–300 K.

Therman Expansion and Crystal Chemistry of (Sr1−x , K2x )Zr4(PO4)6 Ceramic

1995 ◽  
Vol 28 (5) ◽  
pp. 508-512 ◽  
Author(s):  
D.-M. Liu ◽  
L.-J. Lin ◽  
C.-J. Chen
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Thermal Expansion ◽  
High Temperature ◽  
Crystal Chemistry ◽  
X Ray Diffraction ◽  
Lattice Thermal Expansion ◽  
X Ray ◽  
Thermal Expansion Anisotropy ◽  
Sufficient Degree

Thermal expansion of (Sr1−x , K2x )Zr4(PO4)6 (SrKZP) (with x = 0–1) ceramic was investigated using both a dilatometer and a high-temperature X-ray diffractometer. The coefficients of thermal expansion (CTEs) of the SrKZP ceramic measured by the dilatometer demonstrate a similar trend as those from high-temperature X-ray diffraction. Both measurements show an ultra-low CTE at x = 0.5; nevertheless, this composition shows significant lattice thermal-expansion anisotropy (TEA), while the minimum TEA appears with composition x = 0.2. Although it possessed a sufficient degree of TEA, the x = 0.5 composition showed no visible microcracks or negligible microcracks over a grain size as large as 15 μm. A transition of space group from R{\bar 3} to R{\bar 3}c with composition between x = 0.3 and x = 0.5 has been observed. The crystal structure of the SrKZP ceramic with possible occupations of strontium and/or potassium within the lattice in relation to their influence on the CTEs is proposed.

scholarly journals Synthesis, Structure and Thermophysical Properties of Phosphates MNi0.5Zr1.5(PO4)3 (M = Mg, Ca, Sr)

2010 ◽  
Vol 12 (3,4) ◽  
pp. 241 ◽  
Author(s):  
M.V. Sukhanov ◽  
I.A. Schelokov ◽  
V.I. Pet'kov ◽  
E.R. Gobechiya ◽  
Yu.K. Kabalov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heat Capacity ◽  
Thermal Expansion ◽  
High Temperature ◽  
Single Phase ◽  
Rietveld Method ◽  
Type Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Expansion Behavior

<p>New phosphates MNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> (M = Mg, Ca, Sr) were prepared by the precipitating method.<strong><em> </em></strong>Phosphates were characterized using X-ray powder diffraction, IR-spectroscopy and electron microprobe analyses. The crystal structure of phosphates was refined by the Rietveld method. Phosphates CaNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> and SrNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> are shown to have been crystallized in the NaZr<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>-type structure and the phosphate MgNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3 </sub>was obtained as a single-phase with Sc<sub>2</sub>(WO<sub>4</sub>)<sub>3</sub>-type structure. Heat capacity of phosphate CaNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> was measured in the range 7 – 650 K and increased monotonically over the entire temperature range studied. Thermal expansion of phosphate CaNi<sub>0.5</sub>Zr<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> was studied in the interval 295-1073 K by the high temperature X-ray diffraction. This phosphate is similar to the best low-expansion ceramics, such as zircon, cordierite and silica glass in thermal expansion behavior.</p>

β-Ca11B2Si4O22: six-fold twinning, crystal structure and thermal expansion

2018 ◽  
Vol 233 (6) ◽  
pp. 379-390 ◽  
Author(s):  
Sergey N. Volkov ◽  
Valentina A. Yukhno ◽  
Rimma S. Bubnova ◽  
Vladimir V. Shilovskikh
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
High Temperature ◽  
Electron Backscatter Diffraction ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Relationship Of

Abstract The low-temperature polymorph β-Ca11B2Si4O22 crystallizes as a monoclinic structure [space group is P21/c, a=14.059(9), b=6.834(5), c=10.597(7) Å, β=100.735(8)°]. The crystal investigated by single-crystal X-ray diffraction was a twin composed of six individuals. The crystal structure is similar to that of mineral spurrite, Ca5(SiO4)2CO3, and can be described as a framework of [CaO5] and [CaO6] polyhedra, the cavities of which are filled with [SiO4] and [BO3] groups. The orientation relationship of twin domains was investigated by electron backscatter diffraction (EBSD). Thermal expansion was studied by high-temperature X-ray powder diffraction. It is slightly anisotropic: α11=10, α22=16, α33=12×10−6°C−1 at 200°C.

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.

Crystal structure and thermal expansion behavior of oxygen stoichiometric lanthanum strontium manganite at high temperature

2014 ◽  
Vol 256 ◽  
pp. 83-88 ◽  
Author(s):  
Yoshikazu Shirai ◽  
Shin-ichi Hashimoto ◽  
Kazuhisa Sato ◽  
Keiji Yashiro ◽  
Koji Amezawa ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
High Temperature ◽  
Lanthanum Strontium Manganite ◽  
Thermal Expansion Behavior ◽  
Lanthanum Strontium ◽  
Expansion Behavior

Crystal structure and thermal expansion of the low- and high-temperature forms of BaMIV(PO4)2 compounds (M=Ti, Zr, Hf and Sn)

2009 ◽  
Vol 182 (5) ◽  
pp. 1115-1120 ◽  
Author(s):  
D. Bregiroux ◽  
K. Popa ◽  
R. Jardin ◽  
P.E. Raison ◽  
G. Wallez ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
High Temperature
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