  We investigated the dielectric properties of Pb(Fe1/2Nb1/2)1-xTixO3 single
crystals below room temperature. Two dielectric anomalies were detected in
sample A while only one was detected in sample B in the temperature range
90~300 K. A Debye-like relaxation with strong frequency dispersion was detected
in both samples. The pre-edge XAFS suggests that this dielectric anomaly is
induced by the hopping conductivity between Fe2+ and Fe3+. The EXAFS results
give us a clear picture of the local structure of iron ions. The weak frequency
dependent dielectric anomaly only observed in sample A is supposed to be due to
the dipole glass behavior.
