Microstructures Associated with Dielectric and Magnetic Properties in (1-x)BiFeO₃-xBaTiO₃

Abstract

We have investigated microstructures associated with the magnetic and dielectric properties of multiferroic mixed-perovskite compounds of the formula (1- x )BiFeO 3 - x BaTiO 3 by transmission electron microscopy (TEM) combined with conventional dielectric and magnetic measurements. TEM observation revealed that there exist complicated ferroelectric (FE) domains 20–30 nm in size in the FE phase of BiFeO 3 . It was also found that, in an x =0.25 compound, a weak spontaneous magnetization appears in the FE phase at 20 K. From the results of the X-ray and electron diffraction experiments, it is suggested that this weak spontaneous magnetization is closely associated with the decrease in the extent of rhombohedral distortion by a partial substitution of BaTiO 3 for BiFeO 3 .