Проявление структурных фазовых переходов в кристалле Rb-=SUB=-2-=/SUB=-KLuF-=SUB=-6-=/SUB=- в спектрах комбинационного рассеяния света

AbstractThe Raman spectra of an Rb_2KLuF_6 crystal are studied in the temperature range from 8 to 375 K, which includes two phase transitions: one of which proceeds from a cubic to a tetragonal phase, while the other transition takes place from a tetragonal to a monoclinic phase. An analysis of the temperature dependences of parameters of spectral lines shows that the former transition is of the second kind, while the latter transition is of the first kind, close to the tricritical point. It is shown that the structural phase transitions in the Rb_2KLuF_6 double perovskite are not associated with disordering. The former transition is associated with rotations of LuF_6 octahedra around the fourth-order axis, while the latter transition is related with rotations of octahedra and displacements of rubidium ions.

Download Full-text

A Variable-Temperature Hydrostatic Pressure Cell for Raman Scattering Experiments

Applied Spectroscopy ◽

10.1366/0003702864509448 ◽

1986 ◽

Vol 40 (2) ◽

pp. 217-223 ◽

Cited By ~ 6

Author(s):

J. J. Martin ◽

R. Cavagnat ◽

J. C. Cornut ◽

M. Couzi ◽

G. Daleau ◽

...

Keyword(s):

High Pressure ◽

Phase Transitions ◽

Raman Scattering ◽

Variable Temperature ◽

Structural Phase ◽

The Other ◽

Structural Phase Transitions ◽

High Pressure Cell ◽

Pressure Cell ◽

The One

A variable-temperature hydrostatic high-pressure cell for Raman scattering experiments is presented; it can be commonly used for pressures up to about 6 kbars, in the temperature range between 340 and 80 K. Examples of applications are given, concerning conformational equilibriums in liquid tridecane on the one hand, and structural phase transitions in crystalline (CH3)4NMnCl3(TMMC) and (CH3)4NCdCl3 (TMCC), on the other hand.

Download Full-text

Structural phase transitions coupled with prominent dielectric anomalies and dielectric relaxation in a one-dimensional organic–inorganic hybrid compound [C3H4NS][CdCl3]

Journal of Materials Chemistry C ◽

10.1039/c5tc02023a ◽

2015 ◽

Vol 3 (33) ◽

pp. 8535-8541 ◽

Cited By ~ 15

Author(s):

Guang-Quan Mei ◽

Wei-Qiang Liao

Keyword(s):

Phase Transitions ◽

Dielectric Relaxation ◽

Structural Phase ◽

Structural Phase Transitions ◽

Two Phase ◽

Hybrid Compound ◽

Inorganic Hybrid ◽

One Dimensional

A one-dimensional organic–inorganic hybrid exhibits two phase transitions at 288 and 215 K, coupled with remarkable dielectric performances.

Download Full-text

Structural phase transitions at high-temperature in double perovskite Sr2GdRuO6

Physica B Condensed Matter ◽

10.1016/j.physb.2011.12.050 ◽

2012 ◽

Vol 407 (16) ◽

pp. 3150-3154 ◽

Cited By ~ 5

Author(s):

C.A. Triana ◽

L.T. Corredor ◽

D.A. Landínez Téllez ◽

J. Roa-Rojas

Keyword(s):

Phase Transitions ◽

High Temperature ◽

Structural Phase ◽

Double Perovskite ◽

Structural Phase Transitions

Download Full-text

Pressure-induced phase transitions in L-alanine, revisited

Acta Crystallographica Section B Structural Science ◽

10.1107/s010876811001983x ◽

2010 ◽

Vol 66 (4) ◽

pp. 458-471 ◽

Cited By ~ 64

Author(s):

N. A. Tumanov ◽

E. V. Boldyreva ◽

B. A. Kolesov ◽

A. V. Kurnosov ◽

R. Quesada Cabrera

Keyword(s):

Phase Transitions ◽

Raman Spectra ◽

Pressure Range ◽

Monoclinic Phase ◽

Structural Phase ◽

Group Symmetry ◽

Structural Phase Transitions ◽

X Ray Diffraction ◽

X Ray ◽

Cell Parameters

The effect of pressure on L-alanine has been studied by X-ray powder diffraction (up to 12.3 GPa), single-crystal X-ray diffraction, Raman spectroscopy and optical microscopy (up to ∼ 6 GPa). No structural phase transitions have been observed. At ∼ 2 GPa the cell parameters a and b become accidentally equal to each other, but without a change in space-group symmetry. Neither of two transitions reported by others (to a tetragonal phase at ∼ 2 GPa and to a monoclinic phase at ∼ 9 GPa) was observed. The changes in cell parameters were continuous up to the highest measured pressures and the cells remained orthorhombic. Some important changes in the intermolecular interactions occur, which also manifest themselves in the Raman spectra. Two new orthorhombic phases could be crystallized from a MeOH/EtOH/H2O pressure-transmitting mixture in the pressure range 0.8–4.7 GPa, but only if the sample was kept at these pressures for at least 1–2 d. The new phases converted back to L-alanine on decompression. Judging from the Raman spectra and cell parameters, the new phases are most probably not L-alanine but its solvates.

Download Full-text

An organic-inorganic hybrid double perovskite-type cage-like crystal (MA)2KBiCl6 (MA = methylammonium Cation) with dielectric switch behavior

Materials Advances ◽

10.1039/d1ma00691f ◽

2021 ◽

Author(s):

Lin Xiang ◽

Yi-Fang Huang ◽

Yan Feng ◽

Na Wang ◽

Rong-Meng Liao ◽

...

Keyword(s):

Phase Transitions ◽

Structural Analysis ◽

Single Crystal ◽

Structural Phase ◽

Double Perovskite ◽

Structural Phase Transitions ◽

Inorganic Hybrid ◽

Crystal Structural ◽

Perovskite Type

An organic-inorganic hybrid double perovskite-type cage-like crystal, (MA)2KBiCl6 (MA = methylammonium Cation, 1), was synthesized. It undergoes structural phase transitions at 336/326 K (heating/cooling). Various-temperature single-crystal structural analysis reveal that...

Download Full-text

Structural phase transitions coupled with prominent dielectric anomalies and dielectric relaxation in [(CH3)3NH]2[KCo(CN)6] and mixed [(CH3)3NH]2[KFexCo1−x(CN)6] double perovskite hybrids

Dalton Transactions ◽

10.1039/c9dt04703d ◽

2020 ◽

Vol 49 (6) ◽

pp. 1830-1838 ◽

Cited By ~ 1

Author(s):

Magdalena Rok ◽

Bartosz Zarychta ◽

Marcin Moskwa ◽

Błażej Dziuk ◽

Wojciech Medycki ◽

...

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Dielectric Relaxation ◽

Structural Phase Transition ◽

Structural Phase ◽

Double Perovskite ◽

Mixed Crystals ◽

Structural Phase Transitions

Structural phase transition and dielectric anomalies measured in pure and mixed crystals (TrMAFexCo1−x).

Download Full-text

Reversible structural phase transitions and switchable dielectric behaviours in a cyanometallate-based double perovskite-type cage compound: [C3H4NS]2[KCo(CN)6]

Materials Chemistry Frontiers ◽

10.1039/c9qm00724e ◽

2020 ◽

Vol 4 (3) ◽

pp. 918-923 ◽

Cited By ~ 2

Author(s):

Zhi-Xin Gong ◽

Qin-Wen Wang ◽

Jia-Jun Ma ◽

Jia-Ying Jiang ◽

Dian-Yu E ◽

...

Keyword(s):

Phase Transitions ◽

Structural Phase ◽

Double Perovskite ◽

Structural Phase Transitions ◽

Cage Compound ◽

Switch Type ◽

Thermal Vibrations ◽

Reversible Phase ◽

Perovskite Type

Reversible phase transitions in [C3H4NS]2[KCo(CN)6] exhibit switch-type dielectric transitions around 210 K and 237 K. The small displacements and/or thermal vibrations of the cations cause the phase transitions.

Download Full-text