Phase transition filter from controllable hybrid line shape of correlation and squeezing of Pr3+: YPO4 and Eu3+: YPO4

2021 ◽  
Vol 130 (9) ◽  
pp. 093101
Author(s):  
Habib Ullah ◽  
Jinyang Li ◽  
Anas Mujahid ◽  
Yufeng Li ◽  
Yafen Wang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Line Shape ◽  
Hybrid Line

Deuterium NMR Study of the Solid-Solid Phase Transition in Phenethylammonium Bromide

1991 ◽  
Vol 46 (8) ◽  
pp. 691-696 ◽  
Author(s):  
Marco L. H. Gruwel ◽  
Roderick E. Wasylishen
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Line Shape ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
Spin Lattice ◽  
H Nmr ◽  
Line Shapes ◽  
Low Temperature Phase

AbstractUsing 2H NMR, the dynamics of the cation in phenethylammonium bromide were studied in the two solid phases. Line shape and spin-lattice relaxation rate studies of the ammonium headgroups and the adajacent methylene groups indicate the onset of alkyl-chain motion prior to the first order phase transition. In the low-temperature phase the line shape and the spin-lattice relaxation rates of the -ND3 groups are consistent with C3 jumps and an activation energy of 54±4 kJ mol-1. However, in the high-temperature phase the spin-lattice relaxation studies indicate the presence of small-angle diffusion of the -ND3 groups around the C3 symmetry axis. In this phase the -CD2- groups show line shapes typical of large-amplitude two-site jumps occurring at a rate > 107 s-1 . In the low-temperature phase, at temperatures below 295 K, the -CD2- 2H NMR line shapes indicate that the C - D bonds are essentially static

Polarization controlled hybrid line shape and switching of noise correlation via Autler-Town splitting

2017 ◽  
Vol 122 (16) ◽  
pp. 163105
Author(s):  
Changbiao Li ◽  
Irfan Ahmed ◽  
Ghulam A. Khan ◽  
Da Zhang ◽  
Mingyu Xu ◽  
...  
Keyword(s):  
Line Shape ◽  
Noise Correlation ◽  
Hybrid Line

scholarly journals Investigating dirty crossover through fidelity susceptibility and density of states

2014 ◽  
Vol 28 (14) ◽  
pp. 1450083 ◽  
Author(s):  
Ayan Khan ◽  
Saurabh Basu ◽  
B. Tanatar
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Quantum Phase Transition ◽  
Line Shape ◽  
Mean Field ◽  
Disorder Strength ◽  
Statistical Tools ◽  
The Mean ◽  
Field Formalism ◽  
Skewness And Kurtosis

We investigate the BCS–BEC crossover in an ultracold atomic gas in the presence of disorder. The disorder is incorporated in the mean-field formalism through Gaussian fluctuations. We observe evolution to an asymmetric line-shape of fidelity susceptibility (FS) as a function of interaction coupling with increasing disorder strength which may point to an impending quantum phase transition (QPT). The asymmetric line-shape is further analyzed using the statistical tools of skewness and kurtosis. We extend our analysis to density of states (DOS) for a better understanding of the crossover in the disordered environment.

scholarly journals COULOMB BLOCKADE IN GRAPHENE QUANTUM DOTS

2012 ◽  
Vol 27 (01) ◽  
pp. 1350008 ◽  
Author(s):  
QIONG MA ◽  
TAO TU ◽  
LI WANG ◽  
CHEN ZHOU ◽  
ZHI-RONG LIN ◽  
...  
Keyword(s):  
Phase Transition ◽  
Quantum Dots ◽  
Line Shape ◽  
Low Temperatures ◽  
Coulomb Blockade ◽  
Electron Tunneling ◽  
Graphene Quantum Dots ◽  
Single Electron ◽  
Single Electron Tunneling ◽  
Conductance Spectrum

We study the conductance spectrum of graphene quantum dots, both single- and multiple-dot cases. The single electron tunneling through a graphene dot is investigated and the periodicity, amplitude and line shape of the Coulomb blockade oscillations at low temperatures are obtained, which are consistent with the recent experimental observations. Further, we discuss the transport behavior when multiple dots are assembled in array and find a phase transition of conductance spectra from individual Coulomb blockade to collective Coulomb blockade.

The Phase Transition of Corundum-Eskolaite Mineral Series Probed by X-Ray Absorption Spectroscopy

2017 ◽  
Vol 865 ◽  
pp. 15-19
Author(s):  
Natthapong Monarumit ◽  
Wiwat Wongkokua ◽  
Tobias Häger ◽  
Pornsawat Wathanakul ◽  
Somruedee Satitkune
Keyword(s):  
Phase Transition ◽  
Line Shape ◽  
Color Index ◽  
Fine Powder ◽  
Edge Structure ◽  
X Ray ◽  
Ge Detector ◽  
Dark Green ◽  
X Ray Absorption ◽  
Cielab Color

The red color of ruby is caused by Cr3+ impurities substituting Al3+ in Al2O3 structure. The complete substitution of Al3+ by Cr3+ produces Cr2O3 that has the green color. In this study, we focused on the phase transition of solid solution between corundum (Al2O3) and eskolaite (Cr2O3) mineral series. A series of Al2O3-Cr2O3 samples were prepared by mixing fine powder of Al2O3 and Cr2O3 in various ratios. They were ground together and then recrystallized. The obtained crystals were ground again in powder form for X-ray absorption near edge structure (XANES) measurements to avoid polarization dependence. The measurements were carried out at the Cr K-edge absorption energy using a 13-channel array Ge detector in the fluorescence mode. The XANES spectra showed line-shape transitions for 0.125 to 100% variation of Cr2O3. Significant variations in transitions were found when the Cr2O3 content was between 20% and 80%. With Cr2O3 concentration increasing, the sample colors apparently turned from pink to dark green. CIELAB color index measurements were performed. The variations of line-shape spectra of the Al2O3-Cr2O3 samples were found to be consistent with the CIELAB color index results. This Cr K-edge XANES study could be useful for the research in mineral sciences.

Commentary on the NMR apparent phase transition effect in natrolite, fluor-montmorillionite and other systems: Generalizations when the Arrhenius law applies

1976 ◽  
Vol 54 (3) ◽  
pp. 295-300 ◽  
Author(s):  
H. A. Resing ◽  
D. W. Davidson
Keyword(s):  
Phase Transition ◽  
Water Molecule ◽  
Shape Analysis ◽  
Line Shape ◽  
Activation Enthalpy ◽  
Arrhenius Law ◽  
Transition Effect ◽  
Line Shape Analysis ◽  
Mobile Fraction ◽  
The Mean

In situations where the NMR apparent phase transition effect occurs and the Arrhenius rate law is applicable, it has been shown that the mean activation enthalpy is roughly 37 times the temperature at which the mobile fraction is one-half. This and further generalizations have been applied to proton NMR line-shape analysis of water in natrolite and other systems; the mean activation enthalpy for water molecule diffusion in natrolite is estimated to be 18 kcal/mol.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

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.

Dynamic low-dose electron diffraction and imaging of phase transitions in polymers

1993 ◽  
Vol 51 ◽  
pp. 890-891
Author(s):  
David C. Martin ◽  
Jun Liao
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electron Diffraction ◽  
Low Dose ◽  
Dark Field ◽  
Continuous Change ◽  
Selected Area Electron Diffraction ◽  
Resolution Electron ◽  
Chain Axis ◽  
High Resolution Electron Micrographs

By careful control of the electron beam it is possible to simultaneously induce and observe the phase transformation from monomer to polymer in certain solid-state polymcrizable diacetylenes. The continuous change in the crystal structure from DCHD diacetylene monomer (a=1.76 nm, b=1.36 nm, c=0.455 nm, γ=94 degrees, P2l/c) to polymer (a=1.74 nm, b=1.29 nm, c=0.49 nm, γ=108 degrees, P2l/c) occurs at a characteristic dose (10−4C/cm2) which is five orders of magnitude smaller than the critical end point dose (20 C/cm2). Previously we discussed the progress of this phase transition primarily as observed down the [001] zone (the chain axis direction). Here we report on the associated changes of the dark field (DF) images and selected area electron diffraction (SAED) patterns of the crystals as observed from the side (i.e., in the [hk0] zones).High resolution electron micrographs (HREM), DF images, and SAED patterns were obtained on a JEOL 4000 EX HREM operating at 400 kV.

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