Structural and dielectric characterization of Sm2Bi2Ti3O12 ferroelectric ceramics

X-ray diffraction, scanning electron microscopy, and ac impedance techniques have been used to characterize Sm2Bi2Ti3O12 (SmBTO) whose structural and dielectric properties were compared with those of the Bi4Ti3O12 parent ceramic. Impedance response, activation energies, bulk dielectric constant and ferroelectric Curie temperature transition are presented. Results of these ferroelectric materials are analyzed as a function of the crystallite morphology for crystalline-layered Bi4Ti3O12 and polycrystalline plate-like and needle-like Sm2Bi2Ti3O12 ceramics. When samarium substitutes bismuth in BTO, a 100 degrees C decrease of the ferroelectric Curie temperature was observed. (C) 1997 American Institute of Physics.