A Versatile 19-cm-Diameter Low-Temperature Debye-Scherrer Camera

1959 ◽  
Vol 3 ◽  
pp. 41-47
Author(s):  
A. Taylor
Keyword(s):  
Thermal Expansion ◽  
Low Temperature ◽  
Spectral Resolution ◽  
Cooling System ◽  
Lattice Parameters ◽  
Beam Axis ◽  
High Spectral Resolution ◽  
Large Radius ◽  
Diffraction Patterns

AbstractThe camera was constructed to fill the need for a low-temperature instrument capable of yielding high spectral resolution and accurate lattice parameters. Specimen temperatures in the range -190 to 300°C are attainable.A special feature of the camera is the film holder which is split along the beam axis into two symmetrical halves and which can easily be removed from the base without disturbing the cooling system or the specimen. The specimenholderis mounted on a cross-slide to enable specimens of large radius to be rotated off-center with the beam at glancing incidence to their surface. Finally, diffraction patterns from large metallurgical samples may be obtained by removing one of the film holders and employing the apparatus as a “half camera.”Some applications of the camera to the thermal expansion of SiC and MnSe are described.

High spectral resolution / low-temperature IR study of carbonates

2021 ◽  
Author(s):  
Simone De Angelis ◽  
Bernard Schmitt ◽  
Pierre Beck ◽  
Cristian Carli ◽  
Olivier Poch ◽  
...  
Keyword(s):  
Low Temperature ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Ir Study

THERMAL EXPANSION OF LITHIUM, 77° TO 300° K.

1954 ◽  
Vol 32 (11) ◽  
pp. 708-713 ◽  
Author(s):  
W. B. Pearson
Keyword(s):  
Thermal Expansion ◽  
Low Temperature ◽  
Lattice Parameters ◽  
X Ray

Measurements of the lattice parameters of lithium at temperatures below 300° K. have been made and the results are compared with previous work and considered in terms of the Grüneisen relationship. Methods of low temperature X-ray photography are also discussed.

The Synthesis of Metastable Skutterudites and Crystalline Superlattices

2000 ◽  
Vol 626 ◽  
Author(s):  
Heike Sellinschegg ◽  
Joshua R. Williams ◽  
Gene Yoon ◽  
David C. Johnson ◽  
Mike Kaeser ◽  
...  
Keyword(s):  
Low Temperature ◽  
Binary Compound ◽  
Decomposition Temperature ◽  
Lattice Parameters ◽  
Low Temperature Annealing ◽  
Cobalt Compounds ◽  
Ternary Metal ◽  
Diffraction Patterns ◽  
Binary Compounds ◽  
Synthetic Approaches

ABSTRACTWe have used controlled crystallization of elementally modulated reactants to prepare a series of kinetically stable, crystalline skutterudites (M'xM4Sb12 where M' = vacancy, RE, Hf,…; M = Ni, Fe, Co) and crystalline superlattices composed of promising thermoelectric materials. For the bulk synthesis of skutterudites, low angle diffraction data demonstrates that the elemental layers interdiffuse at temperatures below 150°C. Nucleation of the skutterudite structure occurs with at large exotherm on annealing at temperatures below 200°C regardless of the ternary metal. All of the metastable ternary compounds and the new metastable binary compounds were found to decompose exothermically on higher temperature annealing. The decomposition temperature ranged from 250°C for the binary compound NiSb3 to above 550°C for the rare earth containing cobalt compounds. The occupation of the ternary site was found to depend on the composition of the initial reactant and was varied from 0 to 1. Full occupancy typically required an excess of the filling cation. The lattice parameters of the compounds prepared at low temperatures are distinctly smaller than those prepared using traditional synthetic approaches. High temperature annealing converts the lattice parameters of the low temperature compounds to those prepared at higher temperatures using traditional synthetic approaches. Diffraction patterns of crystalline superlattices containing skutterudites prepared using elementally modulated reactants show splitting of high angle diffraction maxima as well as the presence of the expected low angle diffraction pattern from a supperlattice. The skutterudite superlattices are stable with respect to low temperature annealing.

Low-temperature X-ray studies of crystal-lattice parameters and thermal expansion of KTiOPO4 crystals

2000 ◽  
Vol 45 (2) ◽  
pp. 215-218 ◽  
Author(s):  
A. U. Sheleg ◽  
E. M. Zub ◽  
L. A. Stremoukhova ◽  
S. A. Guretskii
Keyword(s):  
Thermal Expansion ◽  
Low Temperature ◽  
Crystal Lattice ◽  
Lattice Parameters ◽  
X Ray ◽  
Crystal Lattice Parameters

Structural and anisotropic thermal expansion correlation of Li2ZrO3at different temperatures

2002 ◽  
Vol 35 (5) ◽  
pp. 634-636 ◽  
Author(s):  
Z. K. Heiba ◽  
Karimat El-Sayed
Keyword(s):  
Thermal Expansion ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Lattice Parameters ◽  
Interatomic Distances ◽  
X Ray ◽  
Anisotropic Thermal Expansion ◽  
Refinement Method ◽  
Different Temperatures ◽  
Diffraction Patterns

Structural and thermal expansion studies of Li2ZrO3were carried out by recording X-ray powder diffraction patterns at five temperatures, 82, 198, 300, 423 and 573 K. The Rietveld refinement method was used for the analysis. There were large anisotropic changes in the lattice parameters as a function of temperature, slight changes in the fractional coordinates of the different atoms, and anisotropic changes in the interatomic distances between the different cations. The correlation of these anisotropies with the structure is considered.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

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