Trap-controlled fractal diffusion model of an atypical dielectric response

Abstract

Within the framework of the multiple trapping and the fractal diffusion equation models a new expression for the complex dielectric permittivity in the frequency domain is found. The new expression allows us to describe an atypical two-power-law dielectric response. An analytical expression for the relaxation time, which is expressed through microscopic parameters of the structural and energy disorder of the system is obtained. Good agreement of the new expression for the complex dielectric permittivity with observed dielectric responses of porous glass composite ADP and nanoscale Si-layered system is demonstrated.