scholarly journals Lattice Thermal Expansion Effects in Pure and Doped Cordierite by Time-of-Flight Neutron Diffraction*

1985 ◽  
Vol 29 ◽  
pp. 173-184 ◽  
Author(s):  
F. K. Predecki ◽  
J. Haas ◽  
J. Faber ◽  
R. L. Hitterman
Keyword(s):  
Thermal Expansion ◽  
Neutron Diffraction ◽  
Powder Diffraction ◽  
Rietveld Method ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Lattice Thermal Expansion ◽  
Space Group ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior

AbstractThe thermal expansion behavior of pure, Ge-doped and Li-doped hexagonal cordierites with respective compositions: 2MgO 2Al2O3 5Si02 2Mg0 2Al2O3 4Si02 Ge02) and 2MgO (2+x)AL203 (5-2x)Si02 xLi20 with x = .174, was investigated using time-of-flight neutron powder diffraction at temperatures from 22 to 750°C in vacuum. The data were refined in space group P6/mcc using the Rietveld method. The lattice thermal expansion curves of all 3 samples were quite similar. The negative axis expansion is associated with (1)displacement of the T2 cations generally toward the axis channels and (2) changes in the distortion of the coupled T1/M tetrahedra/octahedra in the structure. Both contributions were present in all 3 samples but the first was more dominant in the Ge doped sample. The nature and origin of the distortions in T1 and M are discussed.

Preparation and Anisotropic Lattice Thermal Expansion of Hexagonal Cordierite

2017 ◽  
Vol 726 ◽  
pp. 470-477
Author(s):  
Jin Hua Zhang ◽  
Chang Ming Ke ◽  
Hong Dan Wu ◽  
Ji Shun Yu
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Least Squares Method ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
Lattice Thermal Expansion ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Expansion Behavior

The hexagonal cordierite was synthesized by the reverse coprecipitation-calcination method and characterized by powder X-ray diffraction. The lattice thermal expansion behavior of hexagonal cordierite was investigated by high temperature X-ray diffraction in the temperature range 298-1273 K. The lattice parameters of the hexagonal cordierite at different temperature were calculated by a least squares method. The hexagonal cordierite expressed anisotropic thermal expansion behavior with the average lattice thermal expansion coefficient were 2.13×10-6 K-1 along a or b axis and-1.03×10-6 K-1 along c axis from room temperature to 1273 K. The crystal structure of hexagonal cordierite at 298 K and 1273 K were refined by Rietveld method. The thermal expansion coefficient of the height of the [MgO6]-[AlO4] polyhedral layer is-1.8×10-6 K-1. Although the six-member ring expressed the normal positive thermal expansion along arbitrary direction, the height thermal expansion coefficient of the six-member ring is just 0.6×10-6 K-1.

Structure, magnetic properties and thermal expansion of Mn3PtNx (0 ≤ x  ≤ 1.0) compounds

2018 ◽  
Vol 32 (28) ◽  
pp. 1850314 ◽  
Author(s):  
Ruihua Chou ◽  
Ying Sun ◽  
Huiqing Lu ◽  
Guang-Hong Lu
Keyword(s):  
Magnetic Properties ◽  
Thermal Expansion ◽  
Nitrogen Content ◽  
Magnetic Transition ◽  
Spin Correlation ◽  
Solid State Reaction Method ◽  
Volume Effect ◽  
Space Group ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior

In this work, Mn3PtN[Formula: see text] (x = 0, 0.25, 0.5, 0.75 and 1.0) compounds were prepared by solid state reaction method. The structure, magnetic properties and thermal expansion behaviors of Mn3PtN[Formula: see text] compounds with different nitrogen content were systematically investigated. Mn3PtN has typical antiperovskite cubic structure with space group Pm-3m (221). With decreasing nitrogen content, the crystal structure changes to hexagonal with space group P63/mmc when the value of x decreases to x = 0.25, and then back to cubic with Fm3m at x = 0. All of the obtained Mn3PtN[Formula: see text] compound exhibit the magnetic transition from antiferromagnetic (AFM) to paramagnetic (PM). Moreover, another transition from AFM1 to AFM2 at lower temperature was also observed in Mn3Pt. The experimental results indicate that the magnetic transition induced abnormal thermal expansion behavior in Mn3PtN[Formula: see text]. Especially, a typical giant thermal expansion behavior of about [Formula: see text]8‰ volume change arising from the magneto-volume effect at 411 K is observed in Mn3Pt compound. The obtained results imply that this kind of compounds is a strong lattice–spin correlation system.

Structure of ζ-phase plutonium–uranium

1996 ◽  
Vol 52 (1) ◽  
pp. 32-37 ◽  
Author(s):  
A. C. Lawson ◽  
J. A. Goldstone ◽  
B. Cort ◽  
R. J. Martinez ◽  
F. A. Vigil ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Powder Diffraction ◽  
General Pattern ◽  
Neutron Powder Diffraction ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
Space Group ◽  
Elastic Data ◽  
Primitive Unit Cell

The structure of the ζ-phase in the Pu—U system has been determined by neutron powder diffraction. The phase crystallizes in space group R{\bar 3}m with 58 atoms in the primitive unit cell and 10 atoms in the asymmetric unit. The structure is characterized by many short bonds and fits the general pattern of the light actinides. Thermal expansion and elastic data were obtained from the diffraction experiments.

Crystal Structure of La4Si2O7N2Analyzed by the Rietveld Method Using the Time-of-Flight Neutron Powder Diffraction Data

2003 ◽  
Vol 15 (5) ◽  
pp. 1099-1104 ◽  
Author(s):  
Junichi Takahashi ◽  
Hisanori Yamane ◽  
Naoto Hirosaki ◽  
Yoshinobu Yamamoto ◽  
Takayuki Suehiro ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data

ChemInform Abstract: Crystal Structure of Lu4Si2O7N2 Analyzed by the Rietveld Method Using the Time-of-Flight Neutron Powder Diffraction Pattern.

ChemInform ◽  
2010 ◽  
Vol 33 (46) ◽  
pp. no-no
Author(s):  
Junichi Takahashi ◽  
Hisanori Yamane ◽  
Masahiko Shimada ◽  
Yoshinobu Yamamoto ◽  
Naoto Hirosaki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Rietveld Method ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Neutron Powder Diffraction Pattern

Crystal Structure of La4Si2O7N2 Analyzed by the Rietveld Method Using the Time-of-Flight Neutron Powder Diffraction Data.

ChemInform ◽  
2003 ◽  
Vol 34 (22) ◽  
Author(s):  
Junichi Takahashi ◽  
Hisanori Yamane ◽  
Naoto Hirosaki ◽  
Yoshinobu Yamamoto ◽  
Takayuki Suehiro ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data

H/D isotope effect on the molar volume and thermal expansion of benzene

2018 ◽  
Vol 20 (24) ◽  
pp. 16736-16742 ◽  
Author(s):  
A. D. Fortes ◽  
S. C. Capelli
Keyword(s):  
Thermal Expansion ◽  
Molar Volume ◽  
Isotope Effect ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Time Of Flight ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Neutron Powder Diffraction Data ◽  
Invariant Volume

Time-of-flight neutron powder diffraction data have been collected from C6H6 and C6D6 between 10 and 276 K, revealing no cross-over in their molar volumes and an almost temperature invariant volume-isotope-effect, in contrast with previously published work.

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