Negative Thermal Expansion Behaviour in The NZP Phase NbTi(PO4)3

1998 ◽  
Vol 547 ◽  
Author(s):  
D. A. Woodcock ◽  
P. Lightfoot ◽  
R. I. Smith
Keyword(s):  
Thermal Expansion ◽  
Neutron Diffraction ◽  
Volume Expansion ◽  
Negative Thermal Expansion ◽  
Structural Data ◽  
Thermal Expansion Behaviour ◽  
Powder Neutron Diffraction ◽  
Positive Volume ◽  
The Difference ◽  
Expansion Behaviour

AbstractWe present new detailed structural data versus temperature on the Nasicon structured material NbTi(PO4)3 obtained from powder neutron diffraction studies. This material shows a significant volume contraction over the range 20°C < T < 700°C. αa varies between –4.34 and -0.11 × 10-6°C-1 and αc between 0.08 and 3.07 × 10-6°C-1 over this range. This behaviour contrasts with the case of NaTi2(PO4)3 (NaTP) which shows a positive volume expansion. The difference in this behaviour can be explained by the presence of filled MI sites in NaTP which are vacant in the case of NbTP.

A hybrid with uniaxial negative thermal expansion behaviour: the synergistic role of organic and inorganic components

2014 ◽  
Vol 50 (95) ◽  
pp. 14960-14963 ◽  
Author(s):  
Kai-Yao Wang ◽  
Mei-Ling Feng ◽  
Liu-Jiang Zhou ◽  
Jian-Rong Li ◽  
Xing-Hui Qi ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Inorganic Components ◽  
Expansion Behaviour

Through the study on a new Mn2(api)Sb2S5compound, we propose a strategy for designing a novel hybrid with uniaxial NTE behaviour based on the synergistic role of organic and inorganic components.

scholarly journals Compositional Inhomogeneity and Tuneable Thermal Expansion in Mixed-Metal ZIF-8 Analogues

2018 ◽  
Author(s):  
Adam Sapnik ◽  
Harry Geddes ◽  
Emily Reynolds ◽  
Hamish Yeung ◽  
Andrew Goodwin
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Cation Substitution ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Complete Miscibility ◽  
Expansion Behaviour

<div>We study the structural and thermomechanical effects</div><div>of cation substitution in the compositional family of</div><div>metal–organic frameworks Zn1􀀀xCdx(mIm)2 (HmIm = 2-</div><div>methylimidazole). We find complete miscibility for all</div><div>compositions x, with evidence of inhomogeneous distributions of Cd and Zn that in turn affect framework aperture characteristics. Using variable-temperature X-ray powder diffraction measurements, we show that Cd substitution drives a threefold reduction in the magnitude of thermal expansion behaviour. We interpret this effect in terms of an increased density of negative thermal expansion modes in the more flexible Cd-rich frameworks.</div>

scholarly journals Compositional Inhomogeneity and Tuneable Thermal Expansion in Mixed-Metal ZIF-8 Analogues

2018 ◽  
Author(s):  
Adam Sapnik ◽  
Harry Geddes ◽  
Emily Reynolds ◽  
Hamish Yeung ◽  
Andrew Goodwin
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Cation Substitution ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Complete Miscibility ◽  
Expansion Behaviour

<div>We study the structural and thermomechanical effects</div><div>of cation substitution in the compositional family of</div><div>metal–organic frameworks Zn1􀀀xCdx(mIm)2 (HmIm = 2-</div><div>methylimidazole). We find complete miscibility for all</div><div>compositions x, with evidence of inhomogeneous distributions of Cd and Zn that in turn affect framework aperture characteristics. Using variable-temperature X-ray powder diffraction measurements, we show that Cd substitution drives a threefold reduction in the magnitude of thermal expansion behaviour. We interpret this effect in terms of an increased density of negative thermal expansion modes in the more flexible Cd-rich frameworks.</div>

scholarly journals A five-fold interpenetrated metal–organic framework showing a large variation in thermal expansion behaviour owing to dramatic structural transformation upon dehydration–rehydration

2017 ◽  
Vol 53 (5) ◽  
pp. 861-864 ◽  
Author(s):  
Himanshu Aggarwal ◽  
Raj Kumar Das ◽  
Emile R. Engel ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Metal Organic Framework ◽  
Negative Thermal Expansion ◽  
Considerable Change ◽  
Thermal Expansion Coefficients ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Expansion Coefficients ◽  
Expansion Behaviour

A five-fold interpenetrated MOF has the highest uniaxial negative thermal expansion coefficient reported for any interpenetrated MOF to date. Upon dehydration, the framework shows considerable change in the magnitudes of the thermal expansion coefficients.

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
Sign in / Sign up

Export Citation Format

Share Document