  Structural properties, impedance, dielectric and electric modulus spectra
have been used to investigate the sintering temperature (Ts) effect on the
single phase cubic spinel Ni0.6Zn0.4Fe2O4 (NZFO) ceramics synthesized by
standard ceramic technique. Enhancement of dielectric constants is observed
with increasing Ts. The collective contribution of n-type and p-type carriers
yields a clear peak in notable unusual dielectric behavior is successfully
explained by the Rezlescu model. The non-Debye type long range dielectric
relaxation phenomena is explained by electric modulus formalism. Fast response
of the grain boundaries of the sample sintered at lower Ts sample leading to
small dielectric spin relaxation time, t (several nanoseconds) have been
determined using electric modulus spectra for the samples sintered at different
Ts. Two clear semicircles in impedance Cole-Cole plot have also been
successfully explained by employing two parallel RC equivalent circuits in
series configuration taking into account no electrode contribution. Such a long
relaxation time in NZFO ceramics could suitably be used in nanoscale spintronic
devices.
