Anomalous Electrical Relaxation and Polaron Conduction in Nano-crystalline Mn0.5Zn0.5Fe2O4.

Nano-crystalline Mn_0.5Zn_0.5Fe₂O₄ was synthesized by chemical co-precipitation method and characterized with X-ray diffraction. Ac electrical impedance data are taken for the frequency range of 1Hz to 1MHz for various temperatures from 303K to 483K. The ac electrical conduction deviates from the Debye type relaxation which indicates polaron type conduction. In the present study unique anomalous relaxation function in time and frequency domain is used to investigate deviation from the Debye relaxation. The physical basis of anomalous or non-Debye process is explained in terms of change in Debye dipole μ_D=ρr_D of charge ρ into gρ due to the molecular charge interaction and defect disorder. This interaction shifts the Debye relaxation rate τ to a slow relaxation rate τ^g. The fraction 0<g<1 is emerged as the exponent on frequency and time domain function of non-Debye relaxation. [ABSTRACT FROM AUTHOR]