  We have investigated the complex dielectric and impedance properties of
magnetoelectric compound Fe2TiO5 (FTO) as a function of temperature (T) and
frequency (f) to understand the grain (G) and grain boundary (Gb) contributions
to its dielectric response. The temperature and frequency dependent dielectric
permittivity data shows a sharp increase in permittivity above 200K accompanied
with a frequency dependent peak in loss. At T less than 175K, only G
contribution dominates even at lower frequency (nearly 100Hz), but for T
greater than 175K, the Gb contribution starts appearing at low frequency. The
value of critical frequency distinguishing these two contributions increases
with increasing temperature. The observed non-Debye dielectric relaxation
follows thermally activated process and is attributed to polaron hopping.
Further the frequency dependence of ac conductivity follows the Jonscher
power-law. The temperature dependency of critical exponent s shows that the
correlated barrier hopping model is appropriate to define the conductivity
mechanism of FTO in the studied temperature regime.
