Journal ArticleDOI
Structural investigation of the negative-thermal-expansion material ZrW2O8.
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TLDR
Examination of the resulting structural parameters suggests that the origin of the contraction with increasing temperature can be traced straightforwardly to the rigid-body transverse librations of bridging O atoms.Abstract:
High-resolution powder diffraction data have been recorded on cubic ZrW2O8 [a = 9.18000 (3) A at 2 K] at 260 temperatures from 2 to 520 K in 2 K steps. These data have confirmed that α-ZrW2O8 has a negative coefficient of thermal expansion, α = −9.07 × 10−6 K−1 (2–350 K). A `parametric' approach to Rietveld refinement is adopted and it is demonstrated that a full anisotropic refinement can be performed at each temperature, despite using a data collection time of only 5 min. Examination of the resulting structural parameters suggests that the origin of the contraction with increasing temperature can be traced straightforwardly to the rigid-body transverse librations of bridging O atoms. α-ZrW2O8 undergoes a phase transition from P213 to Pa3¯ at 448 K that is associated with the onset of considerable oxygen mobility. The phase transition can be described in terms of a simple cubic three-dimensional Ising model. Unusual kinetics are associated with this phase transition. Hysteresis in the cell parameter through the phase transition is the opposite of that normally observed.read more
Citations
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Negative thermal expansion: a review
TL;DR: In this paper, the state of the art in NTE solids is reviewed, and understanding of the driving mechanisms of the effect is considered along with experimental and theoretical evidence, and various categories of solids with NTE are explored, and experimental methods for their experimental characterisation and applications for such solids are proposed.
Journal ArticleDOI
Negative thermal expansion in the metal-organic framework material Cu3(1,3,5-benzenetricarboxylate)2.
Yue Wu,Atsushi Kobayashi,Atsushi Kobayashi,Gregory J. Halder,Gregory J. Halder,Vanessa K. Peterson,Vanessa K. Peterson,Karena W. Chapman,Nina Lock,Nina Lock,Peter D. Southon,Cameron J. Kepert +11 more
Journal ArticleDOI
Negative thermal expansion and associated anomalous physical properties: review of the lattice dynamics theoretical foundation.
Martin T. Dove,Hong Fang +1 more
TL;DR: This paper identifies a number of different cases of vibrational mechanisms of NTE, some of which involve a small number of phonons that can be described as involving rotations of rigid polyhedral groups of atoms, others where there are large bands of phonon involved, and some where the transverse acoustic modes provide the main contribution to NTE.
Journal ArticleDOI
Large negative linear compressibility of Ag3[Co(CN)6]
TL;DR: It is proposed that framework materials that contract along a specific direction on heating while expanding macroscopically will, in general, also expand along the same direction under hydrostatic pressure while contracting macroscopedically.
Journal ArticleDOI
Direct Observation of a Transverse Vibrational Mechanism for Negative Thermal Expansion in Zn(CN) 2 : An Atomic Pair Distribution Function Analysis
TL;DR: This analysis provides definitive structural confirmation that an increase in the average displacement of bridging atoms is the origin of the NTE behavior.
References
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Journal ArticleDOI
Negative Thermal Expansion from 0.3 to 1050 Kelvin in ZrW2O8
TL;DR: Negative thermal expansion was found for ZrW 2 O 8 from 0.3 kelvin to its decomposition temperature of about 1050 klvin by using both neutron and x-ray diffraction data as mentioned in this paper.
Journal ArticleDOI
The effect of thermal motion on the estimation of bond lengths from diffraction measurements
W. R. Busing,H. A. Levy +1 more
Journal ArticleDOI
Very Low Thermal Expansion Coefficient Materials
TL;DR: In this article, a review of the properties of low-expansion materials is presented, where the authors focus on the anomalously low thermal expansion properties in which there is the greatest interest.
Journal ArticleDOI
Compressibility, Phase Transitions, and Oxygen Migration in Zirconium Tungstate, ZrW2O8
TL;DR: In situ neutron diffraction experiments show that at pressures above 2 kilobars, cubic zirconium tungstate (ZrW2O8) undergoes a quenchable phase transition to an orthorhombic phase, the structure of which has been solved from powder diffraction data.