Dielectric Response in Amorphous Materials Based on Polar Oxides: PbTiO₃, PbFe_1/2Nb_1/2O₃ and PbMg_1/3Nb_2/3O₃

Abstract

The dielectric properties of PbTiO₃, PbFe_1/2Nb_1/2O₃ and PbMg_1/3Nb_2/3O₃ in amorphous and crystallized states have been studied within a temperature range of 20–750 °C. The anomalies of dielectric permittivity ϵ and dielectric losses tgδ caused by crystallization process as well as processes in electron subsystem were revealed. The nature of these anomalies is discussed. The Pb─Pb distances in studied materials have been estimated using X-ray diffraction data.

Keywords:

• Ferroelectrics
• amorphous state
• dielectric permittivity
• X-ray diffraction
• crystallization

Acknowledgments

Authors would like to thanks Dr. O. Ivanov for the help in preparing of the crystalline powder for following quenching of melts to amorphous state.

The work was supported by the Russian Foundation for Basic Research (Grant No. 02-02-16267)