Temperature-dependent studies of a new two-dimensional cadmium dicyanamide framework exhibiting an unusual temperature-induced irreversible phase transition into a three-dimensional perovskite-like framework

2018 ◽  
Vol 20 (47) ◽  
pp. 29951-29958 ◽  
Author(s):  
Mirosław Mączka ◽  
Anna Gągor ◽  
Maciej Ptak ◽  
Dagmara Stefańska ◽  
Adam Sieradzki
Keyword(s):  
Phase Transition ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Temperature Dependent

TPrACd can be grown in both layered and perovskite-like architectures. The layered polymorph transforms irreversibly to the perovskite one at 389 K.

Theory of ultrasonic attenuation in one and two dimensional metals

1976 ◽  
Vol 54 (14) ◽  
pp. 1454-1460 ◽  
Author(s):  
T. Tiedje ◽  
R. R. Haering
Keyword(s):  
Ultrasonic Attenuation ◽  
Three Dimensional ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
One Dimensional ◽  
The Difference

The theory of ultrasonic attenuation in metals is extended so that it applies to quasi one and two dimensional electronic systems. It is shown that the attenuation in such systems differs significantly from the well-known results for three dimensional systems. The difference is particularly marked for one dimensional systems, for which the attenuation is shown to be strongly temperature dependent.

The Effect of Organic Cation Dynamics on the Optical Properties in (PEA)2(MA)[Pb2I7] Perovskite Dimorphs

2021 ◽  
Author(s):  
Lekina Yulia ◽  
Sai Dintakurti ◽  
Benny Febriansyah ◽  
David George Bradley ◽  
Jiaxu Yan ◽  
...  
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Raman Scattering ◽  
Organic Cation ◽  
Two Dimensional ◽  
Lead Iodide ◽  
Temperature Dependent ◽  
Hybrid Perovskite

Two-dimensional (2D) phenylethyl ammonium (PEA+)-methyl ammonium (MA+) lead iodide ((PEA)2(MA)[Pb2I7]) hybrid perovskite exists as temperature-dependent dimorphs exhibiting an ill-defined phase transition occurring over 150 - 200 K range. Raman scattering,...

Structure and Properties of [(CH2OH)3CNH3]H2AsO4

2003 ◽  
Vol 58 (12) ◽  
pp. 722-726 ◽  
Author(s):  
A. Waśkowska ◽  
S. Dacko ◽  
Z. Czapla
Keyword(s):  
Phase Transition ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Dimensional Network ◽  
Network Of Hydrogen Bonds ◽  
Dependent Behaviour

Crystals of [(CH2OH)3CNH3]H2AsO4 have been grown, and X-ray diffraction analysis has shown them to be monoclinic, with space group P21. A three-dimensional network of hydrogen bonds of the type O-H. . . O and N-H. . . O forms strong cation-cation and cation-anion linkages. Stabilizing the structure, they create favourable conditions in the crystal to be polar. The temperature dependent behaviour of the dielectric permittivity, measured along three crystal axes in the range 100 - 300 K, did not show any evidence for a phase transition, while the pyroelectric properties of the crystal confirmed the lack of a centre of symmetry. These polar features locate [(CH2OH)3CNH3]H2AsO4 among the materials applicable to electrooptics and for the second harmonic generation.

Micro-dynamics mechanism of the phase transition behavior of poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) hydrogels revealed by two-dimensional correlation spectroscopy

2017 ◽  
Vol 8 (5) ◽  
pp. 865-878 ◽  
Author(s):  
Gehong Su ◽  
Tao Zhou ◽  
Xifei Liu ◽  
Yanan Ma
Keyword(s):  
Phase Transition ◽  
Ftir Spectroscopy ◽  
Correlation Spectroscopy ◽  
Volume Phase Transition ◽  
Hydroxyethyl Methacrylate ◽  
Two Dimensional ◽  
Phase Transition Behavior ◽  
Temperature Dependent ◽  
Volume Phase ◽  
Transition Behavior

The micro-dynamics mechanism of the volume phase transition of PNIPAM-co-HEMA hydrogels was established using temperature-dependent FTIR spectroscopy, PCMW2D, and 2DCOS analysis.

Zweidimensionales Eis und H5O2+-Ionen. Zur Bildung und Struktur tiefschmelzender molekularer und ionischer Hemi-bis Hexahydrate halogenierter Essigsäuren CClnF3-nCOOH (n = 1 bis 3) [1] / Two-Dimensional Ice and H5O2+ Ions. On Formation and Structure of Low-Melting Molecular and Ionic Hemi-through Hexahydrates of Haloacetic Acids CClnF3-nCOOH (n = 1 to 3) [1]

1996 ◽  
Vol 51 (4) ◽  
pp. 536-544 ◽  
Author(s):  
Thomas Dahlems ◽  
Dietrich Mootz ◽  
Michaela Schilling
Keyword(s):  
Three Dimensional ◽  
Hydrate Formation ◽  
Molecular Structures ◽  
Haloacetic Acids ◽  
Water Molecules ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
X Ray ◽  
Five Phases ◽  
Hydrogen Bonded

Abstract Hydrate formation of haloacetic acids CClnF3-nCOOH (n = 1, 2, 3) has been studied by DTA and temperature-dependent X-ray powder diffraction, and evidence obtained for five phases, all melting at temperatures below ambient. The hydrates have been confirmed and further characterized by their crystal structures at -150 °C. Three lower hydrates, CCl2FCOOH· 0.5H2O (space group P21/c and Z = 8 formula unites per unit cell), CClF2COOHH2O (P21/c, Z = 4), and CClF2COOH ·4H2O (P1̄, Z = 2), have molecular structures with the acid and water molecules hydrogen-bonded in two-dimensional arrays. The structures of the remaining hydrates, CCl2FCOOH·6H2O and CCl3COOH · 6H2O (similar, but not isotypic, both P1̄ and Z = 2), are ionic, as (H5O2+)(CX3COO-) · 4H2O , and three-dimensional. The neutral water molecules are hydrogen-bonded in ice-like layers rare in crystal chemistry. Also, CCl2FCOOH is established only as the second acid of which a lower hydrate is molecular and a higher one ionic.

FIELD INDUCED PHASE TRANSITION FOR SUSPENSION OF MONOSIZED SPHERES

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2357-2363 ◽  
Author(s):  
S. MEN ◽  
A. MEUNIER ◽  
C. MÉTAYER ◽  
G. BOSSIS
Keyword(s):  
Phase Transition ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Horizontal Plane ◽  
Constant Pressure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Ewald Summation ◽  
Dipolar System ◽  
Rotating Field

We have developed a new Ewald summation for a three-dimensional dipolar system with two-dimensional periodicity in a uniaxial field and a rotating field in a horizontal plane. Under a constant pressure and temperature, Monte Carlo simulation has been carried out; phase transitions are found and chainlike structure for a uniaxial field and monolayer or multilayer for rotating field are obtained, which are well consistent with experiments.

The equiatomic intermetallics REPtCd (RE= La, Ce, Pr, Nd, Eu) and magnetic properties of CeAuCd

2015 ◽  
Vol 70 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Michael Johnscher ◽  
Frank Tappe ◽  
Oliver Niehaus ◽  
Rainer Pöttgen
Keyword(s):  
Phase Transition ◽  
Three Dimensional ◽  
Induction Melting ◽  
Antiferromagnetic Phase ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data

AbstractThe cadmium intermetallics REPtCd (RE = La, Ce, Pr, Nd, Eu) and CeAuCd were synthesized by induction-melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. The samples were characterized by powder X-ray diffraction. The structures of CePtCd (ZrNiAl type, $P\bar 62m,$a = 763.8(6), c = 409.1(4) pm, wR2 = 0.0195, 298 F2 values, 14 variables) and EuPtCd (TiNiSi type, Pnma, a = 741.3(2), b = 436.4(1), c = 858.0(4) pm, wR2 = 0.0385, 440 F2 values, 20 variables) were refined from single-crystal data. The REPtCd structures exhibit three-dimensional networks of corner- and edge-sharing Cd@Pt2/6Pt2/3 and Cd@Pt4/4 tetrahedra, which leave cages for the rare earth atoms. Temperature-dependent magnetic susceptibility data of CeAuCd reveal a paramagnetic to antiferromagnetic phase transition at TN = 3.7(5) K.

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