Insituobservation of phase transition in potassium niobate single crystal by synchrotron radiation topography

AbstractThe crystal structure of the copper aluminium phosphate mineral sieleckiite, Cu3Al4(PO4)2 (OH)12·2H2O, from the Mt Oxide copper mine, Queensland, Australia was solved from single-crystal X-ray diffraction data utilizing synchrotron radiation. Sieleckiite has monoclinic rather than triclinic symmetry as previously reported and is space group C2/m with unit-cell parameters a = 11.711(2), b = 6.9233(14), c = 9.828(2) Å, β = 92.88(3)°, V = 795.8(3) Å3and Z = 2. The crystal structure, which has been refined to R1 = 0.0456 on the basis of 1186 unique reflections with Fo > 4σF, is a framework of corner-, edge- and face- sharing Cu and Al octahedra and PO4 tetrahedra.

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Verification of first‐order magnetic phase transition in single crystal iron films

Journal of Applied Physics ◽

10.1063/1.330243 ◽

1982 ◽

Vol 53 (11) ◽

pp. 7966-7968 ◽

Cited By ~ 11

Author(s):

F. J. Rachford ◽

G. A. Prinz ◽

J. J. Krebs ◽

K. B. Hathaway

Keyword(s):

Phase Transition ◽

Single Crystal ◽

Magnetic Phase Transition ◽

Magnetic Phase ◽

Iron Films ◽

First Order ◽

Order Magnetic Phase Transition

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Spontaneous phase transition from relaxor to macrodomain ferroelectric state in single-crystal PbSc0.5Nb0.5O3-BaSc0.5Nb0.5O3 solid solutions

Physics of the Solid State ◽

10.1134/1.1131185 ◽

2000 ◽

Vol 42 (1) ◽

pp. 161-164 ◽

Cited By ~ 23

Author(s):

I. P. Raevskii ◽

V. V. Eremkin ◽

V. G. Smotrakov ◽

E. S. Gagarina ◽

M. A. Malitskaya

Keyword(s):

Phase Transition ◽

Single Crystal ◽

Solid Solutions ◽

Ferroelectric State ◽

Spontaneous Phase

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Single-crystal to single-crystal phase transition of cucurbit[5]uril hydrochloride hydrates: large water-filled channels transforming to layers of unusual stability

Chemical Communications ◽

10.1039/b807033d ◽

2008 ◽

pp. 4927 ◽

Cited By ~ 28

Author(s):

David Bardelang ◽

Konstantin A. Udachin ◽

Roberto Anedda ◽

Igor Moudrakovski ◽

Donald M. Leek ◽

...

Keyword(s):

Phase Transition ◽

Single Crystal ◽

Crystal Phase ◽

Crystal Phase Transition ◽

Large Water

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Phase transition and proton ordering at 50 K in 3-(pyridin-4-yl)pentane-2,4-dione

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520617015591 ◽

2017 ◽

Vol 73 (6) ◽

pp. 1172-1178 ◽

Cited By ~ 4

Author(s):

Khai-Nghi Truong ◽

Carina Merkens ◽

Martin Meven ◽

Björn Faßbänder ◽

Richard Dronskowski ◽

...

Keyword(s):

Phase Transition ◽

Low Temperature ◽

Single Crystal ◽

Structural Phase ◽

Pyridyl Ring ◽

Temperature Phase ◽

Crystallographic Axis ◽

Temperature Phase Transition ◽

Intramolecular Hydrogen ◽

Low Temperature Phase

Single-crystal neutron diffraction experiments at 100 and 2.5 K have been performed to determine the structure of 3-(pyridin-4-yl)pentane-2,4-dione (HacacPy) with respect to its protonation pattern and to monitor a low-temperature phase transition. Solid HacacPy exists as the enol tautomer with a short intramolecular hydrogen bond. At 100 K, its donor···acceptor distance is 2.450 (8) Å and the compound adopts space group C2/c, with the N and para-C atoms of the pyridyl ring and the central C of the acetylacetone substituent on the twofold crystallographic axis. As a consequence of the axial symmetry, the bridging hydrogen is disordered over two symmetrically equivalent positions, and the carbon–oxygen bond distances adopt intermediate values between single and double bonds. Upon cooling, a structural phase transition to the t 2 subgroup P\bar 1 occurs; the resulting twins show an ordered acetylacetone moiety. The phase transition is fully reversible but associated with an appreciable hysteresis in the large single crystal under study: transition to the low-temperature phase requires several hours at 2.5 K and heating to 80 K is required to revert the transformation. No significant hysteresis is observed in a powder sample, in agreement with the second-order nature of the phase transition.

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