Functional Properties of the (1-x)BiFeO3-xBaTiO3 Solid Solutions

Solid solutions of (1-x)BiFeO3-xBaTiO(3) (0 <= x <= 0.30) were prepared by a two-step solid state reaction procedure. After pre-sintering and sintering at 800 degrees C/lh and slow cooling, pure single phase compositions were obtained for all the analyzed mixtures in the limit of XRD accuracy, including for x = 0. A gradual attenuation of the rhombohedral distortion with the increase of BaTiO3 content was found. Small dielectric losses (tan delta < 3%) and permittivities in the range of ( 180, 240) were found for all the compositions at room temperatures. The magnetic investigations shown a composition-dependent ferromagnetism with a maximum magnetization and coercivity for the composition x = 0.05 and perfect antiferromagnetic behavior for the BiFeO3 ceramics. The complex impedance is sensitive to the magnetic field at small temperatures below 300 K, with a stronger variation in the range of fields of (0, 2 T) and a tendency of saturation at higher fields, demonstrating a kind of magnetoelectric coupling, with both magnetocapacitance and magnetoresistence phenomena.