Surface structure and quenching effects in BiFeO3-BaTiO3 ceramics

The structure and properties of Mn-doped 0.67BiFeO(3)-0.33BaTiO(3) ceramics are systematically investigated with respect to the effects of annealing prior to rapid cooling by quenching in air. Air-quenching induces a change in crystal structure from pseudo-cubic to rhombohedral, with higher quenching temperatures leading to an increased rhombohedral distortion. These structural changes are correlated with the appearance of more well-defined ferroelectric domain configurations. It is shown that the surface preparation procedures for XRD measurements can induce significant changes in the peak profiles, indicating differences in crystal structure between the surface and bulk regions. Frequency dispersion in the temperature-dependent relative permittivity for the as-sintered sample is significantly reduced after quenching, accompanied by enhancement of the Curie point and improved temperature-stability of piezoelectric properties. It is proposed that the formation of defect clusters by A-site cation diffusion during cooling is circumvented by quenching, leading to the observed modification of structural distortion and ferroelectric properties.

Automated summary

The structure and properties of Mn-doped 0.67BiFeO(3)-0.33BaTiO(3) ceramics were studied with different treatment conditions. Air-quenching induced changes in crystal structure and the appearance of more defined ferroelectric domain structures. Quenching led to a reduction in frequency dispersion in the temperature-dependent relative permittivity and improved temperature-stability of piezoelectric properties.