Comparative Study of Electronic structure, Optical properties, Lattice dynamics and Thermal expansion behaviour of energetic Ammonium and Potassium dinitramide salts

2021 ◽  
pp. 124645
Author(s):  
Prathap kumar Jharapla ◽  
G. Vaitheeswaran ◽  
M.K. Gupta ◽  
R. Mittal
Keyword(s):  
Thermal Expansion ◽  
Optical Properties ◽  
Electronic Structure ◽  
Comparative Study ◽  
Lattice Dynamics ◽  
Thermal Expansion Behaviour ◽  
Dinitramide Salts ◽  
Expansion Behaviour

Degradation of Rocks, Through Cracking Caused by Differential Thermal Expansion, in Relation to Nuclear Waste Repositories

1981 ◽  
Vol 6 ◽  
Author(s):  
J.R. Mclaren ◽  
R.W. Davidge ◽  
I. Titchell ◽  
K. Sincock ◽  
A. Bromley
Keyword(s):  
Thermal Expansion ◽  
Grain Boundary ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Crack Density ◽  
Granitic Rocks ◽  
Multiphase Materials ◽  
Thermal Expansion Behaviour ◽  
Waste Repositories ◽  
Expansion Behaviour

ABSTRACTHeating to temperatures up to 500°C, gives a reduction in Young's modulus and increase in permeability of granitic rocks and it is likely that a major reason is grain boundary cracking. The cracking of grain boundary facets in polycrystalline multiphase materials showing anisotropic thermal expansion behaviour is controlled by several microstructural factors in addition to the intrinsic thermal and elastic properties. Of specific interest are the relative orientations of the two grains meeting at the facet, and the size of the facet; these factors thus introduce two statistical aspects to the problem and these are introduced to give quantitative data on crack density versus temperature. The theory is compared with experimental measurements of Young's modulus and permeability for various rocks as a function of temperature. There is good qualitative agreement, and the additional (mainly microstructural) data required for a quantitative comparison are defined.

The Thermal Expansion Behaviour of Sulphur Doped GaAs Crystals

1991 ◽  
Vol 126 (1) ◽  
pp. K43-K47 ◽  
Author(s):  
J. Bak-Misiuk ◽  
J. Köhler ◽  
U. Pietsch
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Expansion Behaviour

Thermal expansion behaviour of orthopyroxenes: the role of the Fe-Mn substitution

2015 ◽  
Vol 79 (1) ◽  
pp. 71-87 ◽  
Author(s):  
L. Scandolo ◽  
M. L. Mazzucchelli ◽  
M. Alvaro ◽  
F. Nestola ◽  
F. Pandolfo ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Unit Cell ◽  
Ex Situ ◽  
Thermal Expansion Data ◽  
Compressibility Effect ◽  
Cell Parameters ◽  
Thermal Expansion Behaviour ◽  
Two Samples ◽  
Mn Substitution ◽  
Expansion Behaviour

AbstractTwo Pbca orthopyroxene samples, donpeacorite (DP N.1) and enstatite (B22 N.60) with chemical formulae Mn0.54Ca0.03Mg1.43Si2O6 (XMn = 0.27) and Fe0.54Ca0.03Mg1.43Si2O6 (XFe = 0.27), respectively, were investigated by single-crystal X-ray diffraction at high-temperature conditions.The nearly identical XFe and XMn make the two samples the perfect candidates to investigate the effect of the compositional change at the M2 site (i.e. Fe-Mn substitution) on the thermal expansion behaviour of orthopyroxenes.Therefore, the unit-cell parameter thermal expansion behaviour of both samples has been investigated in the temperature range between room T and 1073 K. No evidence for phase transitions was found over that range. The two samples have been previously disordered with an ex situ annealing at ∼1273 K.The unit-cell parameters and volume thermal expansion data, collected on the disordered samples, have been fitted to a Fei Equation of State (EoS) and the following coefficients obtained: V0 = 853.35(4) Å3, αV,303K = 2.31(24) × 10–5 K–1 and V0 = 845.40(6) Å3, αV,303K = 2.51(25) × 10–5 K–1 for DP N.1 and B22 N.60, respectively.While there is no difference in the volume thermal expansion coefficient as a function of composition and the expansion along the b direction is nearly identical for both samples, slight differences have been found along a and c lattice directions. The thermal expansion along the a direction is counterbalanced by that along c being responsible for the changes in lattice expansion scheme from αb > αc > αa at room T, to αc > αb > αa at high T. Therefore, as a result of the different behaviour along a and c, the unit-cell volume thermal expansion for both samples is identical within estimated standard deviations. The negligible effect of the Fe-Mn substitution on the bulk thermal expansion can be applied when dealing with geothermobarometry based on the elastic host-inclusion approach (e.g. Nestola et al., 2011; Howell et al., 2010; Angel et al., 2014 a, b, 2015). In fact, though the compressibility effect is still not known, the nearly identical thermal expansion coefficients will not affect the entrapment pressure (Pe).

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