Mesoscopic nonequilibrium thermodynamics approach to non-Debye dielectric relaxation
Por:
Hijar H., Mendez-Bermudez, JG, Santamaría-Holek I.
Publicada:
28 feb 2010
Resumen:
Mesoscopic nonequilibrium thermodynamics is used to formulate a model describing nonhomogeneous and non-Debye dielectric relaxation. The model is presented in terms of a Fokker-Planck equation for the probability distribution of noninteracting polar molecules in contact with a heat bath and in the presence of an external time-dependent electric field. Memory effects are introduced in the Fokker-Planck description through integral relations containing memory kernels, which in turn are used to establish a connection with fractional Fokker-Planck descriptions. The model is developed in terms of the evolution equations for the first two moments of the distribution function. These equations are solved by following a perturbative method from which the expressions for the complex susceptibilities are obtained as a function of the frequency and the wave number. Different memory kernels are considered and used to compare with experiments of dielectric relaxation in glassy systems. For the case
Filiaciones:
Hijar H.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico
Santamaría-Holek I.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Unidad Multidisciplinaria Invest & Docencia Juri, Queretaro 76230, Mexico
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