Anomalous dielectric properties of amorphous lead titanate

We studied the effect of a thermal treatment below the crystallization temperature on the dielectric properties of amorphous lead titanate obtained by melt quenching and containing silicon impurity. Anomalies in the permittivity and dielectric losses were observed at 200°C and at a temperature (463°C) corresponding to the ferroelectric phase transition in the crystallized material. The magnitude and shape of these anomalies depend on the thermal prehistory of a sample. The features in the dielectric properties are explained by the presence of a relict polar phase region interacting with the mobile charge carriers.