Dielectric and ferroelectric properties of samarium substituted BaBi4Ti4O15 Aurivillius oxides

Barium bismuth titanate ceramics doped with different concentration of samarium Ba1-(3/2)xSmxBi4Ti4O15, (x=0, 0.05, 0.10, 0.20, 0.30, and 0.40) were prepared by solid state reaction route. X-ray diffraction pattern confirmed that all compositions have a bismuth- layered perovskite structure with an orthorhombic phase of space group A2(1)am. The plate-like grain morphology was observed for the compositions upto (x=0, 0.05, and 0.10) and the shape changed for higher samarium (Sm3+) concentration. FT-IR study confirmed the presence of Bi-O stretching vibrations. The temperature dependent dielectric behavior showed a frequency dependent diffused phase transition above 400 degrees C and a broadening of phase transition with increasing Sm3+ content. The phase transition temperature shifted to higher temperatures with increasing Sm3+ content. Ferroelectric studies revealed that the remanent polarization (P-r) first increased, and then decreased with rising in dopant concentration. The maximum value of remanent polarization (P-r) was found to be 2.40 mu C/cm(2)for x=0.05 composition at an applied electric field of 80 kV/cm. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.