Dielectric Properties of Solid Solutions of BiFeO3 with Pb(Ti, Zr)O3 at High Temperature and High Frequency

Solid solutions of BiFeO3 with PbTiO3, PbTi0.5Zr0.5O3, and PbZrO3 were prepared. The crystallographic data on these solutions, which are basically perovskitic, are given. The dielectric constants of the materials were determined at a frequency of 0.53 GHz and at temperatures up to 800°C. Dielectric Curie points were found in solutions containing up to 90 mole % BiFeO3. These results leave little doubt that BiFeO3 is ferroelectric or antiferroelectric. The extrapolated Curie point for BiFeO3 is above 850°C. BiFeO3 appears more likely to be ferroelectric than antiferroelectric, but the distinction between the two classifications may not be sharp.