A thermo-responsive structural switch and colossal anisotropic thermal expansion in a chiral organic solid

2018 ◽  
Vol 54 (30) ◽  
pp. 3727-3730 ◽  
Author(s):  
Agnieszka Janiak ◽  
Catharine Esterhuysen ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Thermally Induced ◽  
Anisotropic Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Organic Solid ◽  
Polymorphic Forms ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

The apohost form of a chiral trianglimine compound exists in at least three polymorphic forms. Despite similar packing arrangements, only two of these forms exhibit anomalous thermal expansion behaviour, and undergo thermally-induced interconversion.

scholarly journals Hydration-dependent anomalous thermal expansion behaviour in a coordination polymer

2016 ◽  
Vol 52 (15) ◽  
pp. 3231-3234 ◽  
Author(s):  
Prem Lama ◽  
Lukman O. Alimi ◽  
Raj Kumar Das ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Coordination Polymer ◽  
Water Molecules ◽  
Anisotropic Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

A polar coordination polymer has been synthesised that exhibits anomalous anisotropic thermal expansion. The guest water molecules of the as-synthesised complex can be removed on activation without loss of crystal singularity to yield the fully dehydrated form that shows considerably different thermal expansion behaviour compared to its hydrated analogue.

Anomalous thermal expansion of cobalt olivine, Co2SiO4, at low temperatures

2010 ◽  
Vol 43 (4) ◽  
pp. 720-728 ◽  
Author(s):  
Andrew Sazonov ◽  
Vladimir Hutanu ◽  
Martin Meven ◽  
Gernot Heger ◽  
Thomas Hansen ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Structural Parameters ◽  
Quantitative Description ◽  
Lattice Parameter ◽  
Single Crystal Diffraction ◽  
Interatomic Distances ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Capacity Data ◽  
Expansion Behaviour

The temperature variation of the Co2SiO4structural parameters has been investigated by means of both neutron powder and single-crystal diffraction. Measurements were performed in a broad temperature range from 5 to 500 K. There is clear evidence of an anomalous thermal expansion related to the magnetic phase transition at 50 K. Below this temperature an abrupt elongation and contraction were observed along thecandbaxes (space groupPnma), respectively, whereas the lattice parameteraremains constant in the range between 5 and 50 K. The resulting volume of the unit cell is contracted below 50 K. This phenomenon is attributed to magnetostriction effects. A model based on the specific heat capacity data was applied for the quantitative description of the anomalous thermal expansion behaviour. On the other hand, no anomalies can be observed in the temperature dependency of the interatomic distances and angles.

Anomalous thermal expansion behaviour of Ln2Mo4O15 (Ln = Y, Dy, Ho, Tm)

2003 ◽  
Vol 103 (3) ◽  
pp. 289-296 ◽  
Author(s):  
L Sebastian ◽  
S Sumithra ◽  
J Manjanna ◽  
A.M Umarji ◽  
J Gopalakrishnan
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

scholarly journals Phonons and anomalous thermal expansion behaviour in crystalline solids

2018 ◽  
Vol 92 ◽  
pp. 360-445 ◽  
Author(s):  
R. Mittal ◽  
M.K. Gupta ◽  
S.L. Chaplot
Keyword(s):  
Thermal Expansion ◽  
Crystalline Solids ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

Anomalous thermal expansion behaviour of Na8[AlSiO4]6(NO3)2-sodalite: P4̅3n to Pm3̅n phase transition by untilting and contraction of TO4 units

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
C. H. Rüscher ◽  
Th.M. Gesing ◽  
J.-Ch. Buhl
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Single Crystal ◽  
Specific Heat ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

AbstractX-ray single crystal, X-ray powder and specific heat investigations were carried out on alumosilicate NaNO(

scholarly journals Tuning Extreme Anisotropic Thermal Expansion in 1D Coordination Polymers through Metal Selection and Solid Solutions

2021 ◽  
Author(s):  
Lisa van Wyk ◽  
Leigh Loots ◽  
Len Barbour
Keyword(s):  
Thermal Expansion ◽  
Coordination Polymers ◽  
Solid Solutions ◽  
Metal Centre ◽  
Anisotropic Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Expansion Behaviour

The thermal expansion behaviour of a series of 1D coordination polymers has been investigated. Variation of the metal centre allows tuning of the thermal expansion behaviour from colossal positive volumetric...

Accordion and layer-sliding motion to produce anomalous thermal expansion behaviour in 2D-coordination polymers

2019 ◽  
Vol 55 (80) ◽  
pp. 12048-12051 ◽  
Author(s):  
Prem Lama ◽  
Arpan Hazra ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Coordination Polymers ◽  
Solvent Free ◽  
Sliding Motion ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

Solvent free (1) and solvated (2) 2D-coordination polymers have been synthesised where 1 shows the coexistence of linear NTE, PTE and ZTE owing to accordion motion and in 2, lateral sliding of the 2D layers leads to uniaxial NTE.

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.

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