Thermal expansion of corium prepared from UO2 and Zircaloy-2

2012 ◽  
Vol 1444 ◽  
Author(s):  
Shun Hirooka ◽  
Masatoshi Akashi ◽  
Teppei Uchida ◽  
Kyoichi Morimoto ◽  
Masato Kato
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Volume Change ◽  
Thermal Vibration ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Content Ratio ◽  
Diffraction Patterns ◽  
Ar Gas

ABSTRACTIn this study, sintered pellets were prepared from Zircaloy-2 oxide and UO2 as a parameter of content ratio (Zr contents were 0, 24.3, 49.0, 73.4, and 97.9 at% in metal). The sintered pellets were heated in 5%H2/Ar gas. UO2 pellets underwent simple thermal expansion caused by thermal vibration while Zircaloy-2 oxide pellets underwent thermal expansion and volume change with phase transformation. Finally, the 24.3, 49.0, and 73.5 at%Zr-UO2 pellet specimens showed both phenomena. However, phase transformation temperatures were lower than that of Zircaloy-2 oxide, and volume changes were much smaller. X-ray diffraction patterns obtained after thermal expansion measurements showed that the 24.3 at%Zr-UO2 specimen contained tetragonal and cubic (Zr, U)O2 while the 73.5 at%Zr-UO2 specimen contained mainly monoclinic ZrO2.

Thermal expansion and high-temperature phase transformation of the yttrium silicate Y2SiO5

2001 ◽  
Vol 16 (8) ◽  
pp. 2251-2255 ◽  
Author(s):  
J. W. Nowok ◽  
J. P. Kay ◽  
R. J. Kulas
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Linear Thermal Expansion ◽  
Anomalous Behavior ◽  
High Temperature Phase ◽  
Local Order ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yttrium Silicate

The linear thermal-expansion coefficients of yttrium silicate Y2SiO5, [Y2(SiO4)O] were measured in the temperature range from 20 to 1400 °C using x-ray diffraction. The anomalous behavior of thermal expansion was observed above Tc = 850 °C and was attributed to the displacive phase transformation. The transformation was reversible and resulted from the local order °C the compositional disorder and local fluctuation in the elastic free energy constrained a secondary transformation related to the polymorphic twin transformation. This created an additional peak in x-ray diffraction patterns at 2 's intensity. The characteristic of phase transformation both on heating and on cooling of the sample was also investigated using the differential thermal analysis method. The thermogravimetric technique did not indicate on a change of weight at Tc.

Behaviors of the Zr–1.0Sn–0.39Nb–0.31Fe–0.05Cr Alloy at High Temperature

2011 ◽  
Vol 399-401 ◽  
pp. 80-84
Author(s):  
Yi Yuan Tang ◽  
Jie Li Meng ◽  
Kai Lian Huang ◽  
Jian Lie Liang
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
High Temperature ◽  
Oxide Film ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thin Oxide Film ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Phase transformation of the Zr-1.0Sn-0.39Nb-0.31Fe-0.05Cr alloy was investigated by high temperature X-ray diffraction (XRD). The XRD results revealed that the alloy contained two precipitates at room temperature, namely β-Nb and hexagonal Zr(Nb,Fe,Cr,)2. β-Nb was suggested to dissolve into the α-Zr matrix at the 580oC. Thin oxide film formed at the alloy’s surface was identified as mixture of the monoclinic Zr0.93O2and tetragonal ZrO2, when the temperature reached to 750oC and 850 oC. The thermal expansion coefficients of αZr in this alloy was of αa = 8.39×10-6/°C, αc = 2.48×10-6/°C.

EFFECT OF PYRIDINE INTERCALATION ON SEMICONDUCTOR CRYSTALLINE MnPS3 MATERIALS PHASE TRANSFORMATION

2010 ◽  
Vol 09 (03) ◽  
pp. 215-223 ◽  
Author(s):  
A. A. EL-MELIGI ◽  
A. M. AL-SAIE ◽  
H. AL-BUFLASA ◽  
M. BOUOUDINA
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Crystallite Size ◽  
Inorganic Compounds ◽  
Semiconductor Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystalline Semiconductor ◽  
Diffraction Patterns ◽  
Three Phases

The crystalline semiconductor material (MnPS3) has interlayer d-spacing gap of 6.4 Å. The main advantage of this gap is the ability to accommodate organic and inorganic compounds. Pyridine was intercalated in the MnPS3 interlayer gap under specific conditions. Four phases (d-spacing = 12.48 Å, 10.8 Å, 9.7 Å and 7.3 Å) were observed and the corresponding lattice expansions were determined, 5.8 Å, 4.4 Å, 3.3 Å and 1 Å, respectively. X-ray diffraction patterns of the samples after the experiment were stopped to reveal the presence of three phases together. The phase transformation occurred for the aforementioned phases. The crystallite size of certain phases is within nanorange. The magnetic properties of the materials are affected by the phase transformation. Complete intercalation was confirmed by the XRD and infrared (IR) measurements.

Thermal analysis of the phases of HMX using X-ray diffraction

1993 ◽  
Vol 204 (1) ◽  
Author(s):  
M. Herrmann ◽  
W. Engel ◽  
N. Eisenreich
Keyword(s):  
Thermal Analysis ◽  
Thermal Expansion ◽  
Phase Transitions ◽  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Temperature Range

AbstractThe 4 phases of HMX and its transitions were investigated using X-ray diffraction. The phases were heated stepwise in a temperature range from 170 K to 510 K, measuring a diffraction pattern after each step.The thermal expansion of the different phases and the volume changes during the phase transitions were obtained. Anomalies and strongly anisotropic expansions were observed withThe highest thermal expansion was found with

CTEAS: a graphical-user-interface-based program to determine thermal expansion from high-temperature X-ray diffraction

2013 ◽  
Vol 46 (2) ◽  
pp. 550-553 ◽  
Author(s):  
Z.A. Jones ◽  
P. Sarin ◽  
R. P. Haggerty ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensions ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Lattice Constants ◽  
Thermal Expansion Tensor ◽  
Different Temperatures ◽  
Diffraction Patterns

The coefficient of thermal expansion analysis suite (CTEAS) has been developed to calculate and visualize thermal expansion properties of crystalline materials in three dimensions. The software can be used to determine the independent terms of the second-rank thermal expansion tensor usinghklvalues, correspondingdhkllistings and lattice constants obtained from powder X-ray diffraction patterns collected at different temperatures. UsingCTEAS, a researcher can also visualize the anisotropy of this essential material property in three dimensions. In-depth understanding of the thermal expansion of crystalline materials can be a useful tool in understanding the dependence of the thermal properties of materials on temperature when correlated with the crystal structure.

scholarly journals Structural and Dielectric Properties of (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) Nanocomposites

2021 ◽  
Author(s):  
A. Mallikarjuna ◽  
N. Suresh Kumar ◽  
T. Anil Babu ◽  
S. Ramesh ◽  
Chandra Babu Naidu K
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
Dielectric Behavior ◽  
Perfect Absorber ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Diffraction Patterns

Abstract (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) [ALTBZFO] nanocomposites were synthesized via hydrothermal method. The X-ray diffraction patterns indicated the phase transformation from tetragonal to cubic for x = 0.2 to 0.4 - 0.8 samples, respectively. The surface morphology showed the existence of nanospheres like structures. At 1 MHz frequency also, the dielectric constant was increased from 230 to 710 for x = 0.2 – 0.6 samples, respectively. But, interestingly, x = 0.6 nanocomposite exhibited the negative dielectric behavior having the dielectric constant (ε') ~ -58.5 and dielectric loss (ε") ~ -417 at 8 MHz. Likewise, x = 0.6 sample showed ac-electrical conductivity (σac) -0.159 S/cm at 6 MHz. Hence, these kinds of materials can provide high charge stored capacitor, and perfect absorber applications.

scholarly journals Unusual Breathing Behavior of Optically Excited Barium Titanate Nanocrystals

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 365
Author(s):  
Jiecheng Diao ◽  
Mathew Cherukara ◽  
Ross Harder ◽  
Xiaojing Huang ◽  
Fucai Zhang ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Barium Titanate ◽  
Free Electron Laser ◽  
Laser Excitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Contacts ◽  
Diffraction Peaks ◽  
Diffraction Patterns ◽  
Transfer Direction

Coherent X-ray diffraction patterns were recorded by using an X-ray free-electron laser to illuminate barium titanate nanocrystals as a function of time delay after laser excitation. Rather than seeing any significant thermal expansion effects, the diffraction peaks were found to move perpendicular to the momentum transfer direction. This suggests a laser driven rotation of the crystal lattice, which is delayed by the aggregated state of the crystals. Internal deformations associated with crystal contacts were also observed.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

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