Contributions of Dipolar Relaxation Processes and Ionic Transport to the Response of Liquids to Electrical Perturbation Fields

2011 ◽  
Vol 115 (19) ◽  
pp. 5730-5740 ◽  
Author(s):  
M. J. Sanchis ◽  
P. Ortiz-Serna ◽  
M. Carsí ◽  
R. Díaz-Calleja ◽  
E. Riande ◽  
...  
Keyword(s):  
Ionic Transport ◽  
Relaxation Processes ◽  
Dipolar Relaxation

scholarly journals The Influence of the Ceramic Nanoparticles on the Thermoplastic Polymers Matrix: Their Structural, Optical, and Conductive Properties

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2773
Author(s):  
Ion Smaranda ◽  
Andreea Nila ◽  
Paul Ganea ◽  
Monica Daescu ◽  
Irina Zgura ◽  
...  
Keyword(s):  
Weight Ratio ◽  
Relaxation Processes ◽  
X Ray Diffraction ◽  
Thermoplastic Polymers ◽  
Dipolar Relaxation ◽  
Ceramic Nanoparticles ◽  
Preferential Adsorption ◽  
Conductive Properties ◽  
Ir Bands ◽  
Pl Quenching

This paper prepared composites under the free membranes form that are based on thermoplastic polymers of the type of polyurethane (TPU) and polyolefin (TPO), which are blended in the weight ratio of 2:1, and ceramic nanoparticles (CNs) such as BaSrTiO3 and SrTiO3. The structural, optical, and conductive properties of these new composite materials are reported. The X-ray diffraction studies highlight a cubic crystalline structure of these CNs. The main variations in the vibrational properties of the TPU:TPO blend induced by CNs consist of the following: (i) the increase in the intensity of the Raman line of 1616 cm−1; (ii) the down-shift of the IR band from 800 to 791 cm−1; (iii) the change of the ratio between the absorbance of IR bands localized in the spectral range 950–1200 cm−1; and (iv) the decrease in the absorbance of the IR band from 1221 cm−1. All these variations were correlated with a preferential adsorption of thermoplastic polymers on the CNs surface. A photoluminescence (PL) quenching process of thermoplastic polymers is demonstrated to occur in the presence of CNs. The anisotropic PL measurements have highlighted a change in the angle of the binding of the TPU:TPO blend, which varies from 23.7° to ≈49.3° and ≈53.4°, when the concentration of BaSrTiO3 and SrTiO3 CNs, respectively, is changed from 0 to 25 wt. %. Using dielectric spectroscopy, two mechanisms are invoked to take place in the case of the composites based on TPU:TPO blends and CNs, i.e., one regarding the type of the electrical conduction and another specifying the dielectric–dipolar relaxation processes.

scholarly journals Monopolar and dipolar relaxation in spin ice Ho2Ti2O7

2021 ◽  
Vol 7 (25) ◽  
pp. eabg0908
Author(s):  
Yishu Wang ◽  
T. Reeder ◽  
Y. Karaki ◽  
J. Kindervater ◽  
T. Halloran ◽  
...  
Keyword(s):  
Bound States ◽  
Elevated Temperatures ◽  
Magnetic Monopoles ◽  
Atomic Scale ◽  
Relaxation Processes ◽  
Spin Ice ◽  
Coulomb Interactions ◽  
Relaxation Dynamics ◽  
Dipolar Relaxation ◽  
New Class

Ferromagnetically interacting Ising spins on the pyrochlore lattice of corner-sharing tetrahedra form a highly degenerate manifold of low-energy states. A spin flip relative to this “spin-ice” manifold can fractionalize into two oppositely charged magnetic monopoles with effective Coulomb interactions. To understand this process, we have probed the low-temperature magnetic response of spin ice to time-varying magnetic fields through stroboscopic neutron scattering and SQUID magnetometry on a new class of ultrapure Ho2Ti2O7 crystals. Covering almost 10 decades of time scales with atomic-scale spatial resolution, the experiments resolve apparent discrepancies between prior measurements on more disordered crystals and reveal a thermal crossover between distinct relaxation processes. Magnetic relaxation at low temperatures is associated with monopole motion through the spin-ice vacuum, while at elevated temperatures, relaxation occurs through reorientation of increasingly spin-like monopolar bound states. Spin fractionalization is thus directly manifest in the relaxation dynamics of spin ice.

Investigation of Dipolar Relaxation Processes in a Side-Chain Nonlinear Optical Polymer

1996 ◽  
Vol 446 ◽  
Author(s):  
Z. -Y. Cheng ◽  
R. S. Katiyar ◽  
S. Bauer ◽  
S. Bauer-Gogonea
Keyword(s):  
Glass Transition ◽  
Dielectric Spectroscopy ◽  
Nonlinear Optical ◽  
Side Chain ◽  
Relaxation Processes ◽  
Dipolar Relaxation ◽  
Depolarization Current ◽  
Chain Polymer ◽  
Optical Polymer ◽  
Nonlinear Optical Polymer

AbstractAmorphous thin films of a typical side-chain nonlinear optical polymer were investigated by means of dielectric spectroscopy and thermally stimulated depolarization current (TSDC) within the temperature range -40°C to 230°C. Three distinct relaxation processes, labelled α, β and γ were observed. The α-relaxation, associated with the glass transition, is well described by the Vogel-Fulcher relation, while the sub glass transition β and γ-relaxation follow Arrhenius relations. The advantage of TSDC over dielectric spectroscopy is demonstrated for the investigation of the weak β-relaxation in the side-chain polymer. Furthermore, the β -relaxation is responsible for the initial, fast decay of the electro-optical response of the side-chain polymer at room temperature.

Coherent vibrations in percolative oil-resin systems: A Böse condensation effect observed by the technique of thermostimulated currents

1999 ◽  
Vol 14 (2) ◽  
pp. 606-614
Author(s):  
O. Pagès ◽  
M. Grimau ◽  
A. Lamure ◽  
A. Zaoui ◽  
B. Legendre
Keyword(s):  
Bose Condensation ◽  
Relaxation Processes ◽  
Dipolar Relaxation ◽  
Conducting Phase ◽  
Correlated Motions ◽  
Condensation Effect ◽  
Coherent Vibration ◽  
Thermostimulated Currents ◽  
Insulating Phase ◽  
First Time

The analysis of thermostimulated currents by the fractional polarization procedure is used to understand percolative behaviors in conductor-insulator-like oil-resin mixtures. On the fundamental side oil-poor systems are particularly attractive. They offer for the first time the opportunity to apply a pure Debye-like dielectric treatment of the quasi-elastic dipolar relaxation since the involved dipoles are independent, associated with spatially separated bounded clusters. An unusual compensation phenomenon is observed in the sense that first it does not describe hierarchically correlated motions and secondly it is related to the conducting phase but exhibits characteristics of the insulating phase. This compensation phenomenon is interpreted within the framework of Fröhlich's approach of relaxation processes in biological materials, as significative of a coherent vibration resulting from Böse condensation effects. On the practical side, the surveillance of this compensation phenomenon appears to be a new way to follow the coalescence of conducting bounded clusters with aging.

Dielectric studies of dipolar relaxation processes in nylon 11

2000 ◽  
Vol 33 (15) ◽  
pp. 1921-1931 ◽  
Author(s):  
R M Neagu ◽  
E Neagu ◽  
A Kyritsis ◽  
P Pissis
Keyword(s):  
Relaxation Processes ◽  
Dielectric Studies ◽  
Dipolar Relaxation ◽  
Nylon 11

Recombination of Optically Excited Carriers in a-Si:H at Low temperatures and Intermediate Times

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Whitaker ◽  
T. Su ◽  
P. C. Taylor
Keyword(s):  
Electron Spin Resonance ◽  
Low Temperatures ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Dipolar Relaxation ◽  
Spin Lattice ◽  
Carrier Recombination ◽  
Nmr Data ◽  
Spin Resonance ◽  
Time Regime

AbstractOptically induced electron spin resonance (LESR) studies on time scales in between the previously published PL and LESR results (approximately 10 ms to 10 s) allow one to examine the cross over between energy-loss (downward) hopping of carriers and carrier recombination via tunneling. In addition, data in this time regime are directly compared in the same sample with NMR data on the dipolar spin-lattice relaxation of the bonded hydrogen where light induced electrons and holes are responsible for dipolar relaxation of bonded hydrogen. The LESR results confirm the interpretation of the NMR measurements.

Activation energy of relaxation processes in chalcogenide glasses

2013 ◽  
Vol 34 (0) ◽  
pp. 59-63
Author(s):  
А. А. Горват ◽  
В. М. Кришеник ◽  
А. Е. Кріштофорій ◽  
В. В. Мінькович ◽  
О. А. Молнар
Keyword(s):  
Activation Energy ◽  
Chalcogenide Glasses ◽  
Relaxation Processes
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