The dielectric properties of (1-x)Pb(Fe2/3W1/3)O-3. xPbTiO(3) solid solutio
ns were investigated from 10(2) to 10(6) Hz in the temperature range 150-60
0 K. The phase transition of Pb(Fe2/3W1/3)O-3 (PFW) was shifted by PbTiO3 (
PT) additions to higher temperatures at a rate of 6.3 K/mol% of PT. The tem
perature dependence of dielectric permittivity showed a sharper transition
as the PT content increased, Dielectric measurements in a wide temperature
range showed the presence of a second set of dielectric peaks at higher tem
peratures (350-600 K), besides the ferroelectric-paraelectric phase transit
ion, This second set of peaks vanished when the samples were annealed in ni
trogen. The activation energy values for the second relaxation varied betwe
en 0.50 and 0.63 eV, in agreement with the conduction activation energy det
ermined for each sample. This relaxation is apparently related to electron
holes.