scholarly journals Broadband light scattering of two relaxation processes in relaxor ferroelectric0.93Pb(Zn1/3Nb2/3)O3−0.07PbTiO3single crystals

2008 ◽  
Vol 78 (14) ◽  
Author(s):  
Shinya Tsukada ◽  
Seiji Kojima
Keyword(s):  
Light Scattering ◽  
Relaxation Processes

Fast relaxation processes in glasses as revealed by depolarized light scattering

2007 ◽  
Vol 353 (16-17) ◽  
pp. 1491-1500 ◽  
Author(s):  
S.V. Adichtchev ◽  
N.V. Surovtsev ◽  
J. Wiedersich ◽  
A. Brodin ◽  
V.N. Novikov ◽  
...  
Keyword(s):  
Light Scattering ◽  
Relaxation Processes ◽  
Fast Relaxation ◽  
Depolarized Light Scattering

Light scattering studies of high-frequency relaxation processes in organic glass formers

1996 ◽  
Vol 8 (47) ◽  
pp. 9593-9598 ◽  
Author(s):  
R M Pick ◽  
A Aouadi ◽  
C Dreyfus ◽  
R Torre ◽  
P Bartolini
Keyword(s):  
Light Scattering ◽  
High Frequency ◽  
Organic Glass ◽  
Relaxation Processes ◽  
Frequency Relaxation

scholarly journals Упругие свойства растворов гуанидин гидрохлорида различной концентрации в гигагерцовом диапазоне частот

2020 ◽  
Vol 90 (9) ◽  
pp. 1546
Author(s):  
А.И. Федосеев ◽  
И.П. Колударов ◽  
А.В. Фронтцек ◽  
А.В. Дмитриев ◽  
С.Г. Лушников
Keyword(s):  
Activation Energy ◽  
Light Scattering ◽  
Guanidine Hydrochloride ◽  
Adiabatic Compressibility ◽  
Relaxation Processes ◽  
Arrhenius Law ◽  
Absolute Value ◽  
Thermally Activated ◽  
Low Concentrations ◽  
Temperature Dependences

Temperature dependences of hypersound velocity V(T) in solutions with different guanidine hydrochloride (GdnHCl) concentrations have been studied by Brillouin light scattering at temperatures from 263 to 353 K. It has been shown that for low GdnHCl concentrations the V(T) dependence has a pronounced maximum. An increase in the GdnHCl concentration in the solution is accompanied by a shift of the maximum towards lower temperatures and also an increase in the absolute value of hypersound velocity and, hence, a decrease in the adiabatic compressibility in the entire temperature range studied. The temperature dependence of adiabatic compressibility at low concentrations of GndHCl is ploted. The contribution of relaxation processes to the temperature behavior of hypersound attenuation in GndHCl solutions is determined. It is shown that their behavior is thermally activated and described by Arrhenius ' law. The values of activation energy of relaxation processes are calculated. Possible mechanisms underlying the effects observed are considered.

Dielectric and Optical Properties of Polymer Confined in Random Porous Matrices

2005 ◽  
Vol 899 ◽  
Author(s):  
Fouad Aliev
Keyword(s):  
Glass Transition ◽  
Light Scattering ◽  
Average Pore Size ◽  
Orientational Order ◽  
Pore Wall ◽  
Molecular Structures ◽  
Relaxation Processes ◽  
Average Pore ◽  
Porous Matrices ◽  
Dielectric And Optical Properties

AbstractWe report the results of the investigations of the influence of confinement on the glass transition and dynamics of the a-relaxation processes in poly(octylmethacrylate) (POMA) by dielectric spectroscopy. The polymer was synthesized directly in pores of the porous glass matrix with interconnected and randomly oriented pores with an average pore size of 100 nm by free radical polymerization of the monomer. We found that confinement is resulted in the reduction of the glass transition temperature Tg of the polymer. This change in Tg was mainly due to the existence of a developed pore wall-polymer interface and difference in the dynamic behavior of polymer in the surface layers compared to that in the bulk. Complementary light scattering experiments show that in 100 nm matrices containing the polymer an anomalous change in light scattering, which switches the composite from the opaque state to the transparent, in a narrow temperature range around T = 60 °C. These changes could be explained by assuming that at low temperatures (opaque state) the orientational order of the relatively long linear aliphatic side groups is induced by the inner pore surface. The assumption of the formation of the orientationally ordered regions at the pore wall in confined POMA is in agreement with the molecular structures of the polymer and the surface of silica.

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