Proton dynamics in the room-temperature phase of Cs3(HSO4)2(H2PO4) studied by 1H MAS NMR

2007 ◽  
Vol 178 (27-28) ◽  
pp. 1493-1498 ◽  
Author(s):  
H OMI ◽  
K SUZUKI ◽  
S HAYASHI
Keyword(s):  
Room Temperature ◽  
Mas Nmr ◽  
Temperature Phase ◽  
1H Mas Nmr ◽  
Proton Dynamics

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

scholarly journals Structure and Properties of Ln2MoO6 Oxymolybdates (Ln = La, Pr, Nd) Doped with Magnesium

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Ekaterina Orlova ◽  
Elena Kharitonova ◽  
Timofei Sorokin ◽  
Alexander Antipin ◽  
Nataliya Novikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
Hygroscopic Properties ◽  
Thermogravimetric Studies ◽  
Mg Doped

The literature data and the results obtained by the authors on the study of the structure and properties of a series of polycrystalline and single-crystal samples of pure and Mg-doped oxymolybdates Ln2MoO6 (Ln = La, Pr, Nd) are analyzed. Presumably, the high-temperature phase I41/acd of Nd2MoO6 single crystals is retained at room temperature. The reason for the loss of the center of symmetry in the structures of La2MoO6 and Pr2MoO6 and the transition to the space group I4¯c2 is the displacement of oxygen atoms along the twofold diagonal axes. In all structures, Mg cations are localized near the positions of the Mo atoms, and the splitting of the positions of the atoms of rare-earth elements is found. Thermogravimetric studies, as well as infrared spectroscopy data for hydrated samples of Ln2MoO6 (Ln = La, Pr, Nd), pure and with an impurity of Mg, confirm their hygroscopic properties.

Betaine arsenate, (CH3)3NCH2COO · D3AsO4: structure refinement using multiple-wavelength synchrotron radiation data

1997 ◽  
Vol 212 (9) ◽  
Author(s):  
S. Kek ◽  
M. Grotepaß-Deuter ◽  
K. Fischer ◽  
K. Eichhorn
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Room Temperature ◽  
Structure Refinement ◽  
Temperature Phase ◽  
Space Group ◽  
Radiation Data ◽  
Multiple Wavelength

AbstractThe crystal structure of deuterated betaine arsenate, (CHThe both paraelectric and ferroelastic room-temperature phase of betaine arsenate crystallizes in space group

Single-Crystal X-Ray Scattering Study of Superstructures and Phase Transitions in Graphite-Hno3 and Graphite-Br2 Intercalation Compounds

1982 ◽  
Vol 20 ◽  
Author(s):  
R. Moret ◽  
R. Comes ◽  
G. Furdin ◽  
H. Fuzellier ◽  
F. Rousseaux
Keyword(s):  
Phase Transitions ◽  
Low Temperature ◽  
Room Temperature ◽  
Temperature Phase ◽  
Temperature Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Temperature Liquid ◽  
Low Temperature Phase

ABSTRACTIn α-C5n-HNO3 the condensation of the room-temperature liquid-like diffuse ring associated with the disorder-order transition around 250 K is studied and the low-temperature. superstructure is examined.It is found that β-C8n-HNO3 exhibits an in-plane incommensurate order at room temperature.Two types of graphite-Br2 are found. Low-temperature phase transitions in C8Br are observed at T1 ≍ 277 K and T2 ≍ 297 K. The room-temperature structure of C14Br is reexamined. Special attention is given to diffuse scattering and incommensurability.

Identification of the OH groups responsible for kinetic basicity on MgO surfaces by 1H MAS NMR

2009 ◽  
Vol 268 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Céline Chizallet ◽  
Hugo Petitjean ◽  
Guylène Costentin ◽  
Hélène Lauron-Pernot ◽  
Jocelyne Maquet ◽  
...  
Keyword(s):  
Mas Nmr ◽  
1H Mas Nmr ◽  
Oh Groups

1H mas NMR and IR studies of the acidic properties of realuminated zeolite Y

1989 ◽  
Vol 3 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Jacek Klinowski ◽  
Halimaton Hamdan ◽  
Avelino Corma ◽  
Vincente Forn�s ◽  
Michael Hunger ◽  
...  
Keyword(s):  
Zeolite Y ◽  
Mas Nmr ◽  
Acidic Properties ◽  
1H Mas Nmr ◽  
Ir Studies

scholarly journals Phonons, electrons and thermal transport in Planckian high Tc materials

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Connie H. Mousatov ◽  
Sean A. Hartnoll
Keyword(s):  
Thermal Diffusivity ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Temperature Phase ◽  
Temperature Derivative ◽  
High Tc ◽  
Optimal Doping ◽  
Strong Scattering ◽  
Measured Strength ◽  
Temperature Phase Diagram

AbstractThe room-temperature thermal diffusivity of high Tc materials is dominated by phonons. This allows the scattering of phonons by electrons to be discerned. We argue that the measured strength of this scattering suggests a converse Planckian scattering of electrons by phonons across the room-temperature phase diagram of these materials. Consistent with this conclusion, the temperature derivative of the resistivity of strongly overdoped cuprates is noted to show a kink at a little below 200 K that we argue should be understood as the onset of a high-temperature Planckian T-linear scattering of electrons by classical phonons. This kink continuously disappears toward optimal doping, even while strong scattering of phonons by electrons remains visible in the thermal diffusivity, sharpening the long-standing puzzle of the lack of a feature in the T-linear resistivity at optimal doping associated with the onset of phonon scattering.

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