Dielectric and ferroelectric properties of lead-free Ba_1−xLa_xTi_1−xFe_xO₃ ceramics

H. Chaabane (1) , Najmeddine Abdelmoula (1) , Hamadi Khemakhem (1) , Annie Simon (2) , Dominique Michau (2) , Mario Maglione (2)

1 LMF - Laboratoire des Matériaux Ferroélectriques
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Perovskite types Ba_1−xLa_xTi_1−xFe_xO₃ (with 0 ≤ x ≤ 0.15) ceramics have been prepared through a solid-state reaction route. The room-temperature X-ray diffraction study suggests that all the compositions have single phase. A broad dielectric anomaly coupled with the shift of dielectric maxima toward a higher temperature with increasing frequency indicates the relaxor-type behavior in some ceramics. The relaxor ceramics obtained obey the Vogel–Fulcher law. The partial replacement of Ba²⁺ by La³⁺ and Ti⁴⁺ by Fe³⁺ shows a remarkable decrease of T_C. The P–E hysteresis measurement proves the ferroelectric character of these compounds. The piezoelectric constant d₃₁ of about 33.7 pC N⁻¹ was observed for Ba_0.95La_0.05Ti_0.95Fe_0.05O₃ ceramic.

Domaines: Matériaux

H. Chaabane, Najmeddine Abdelmoula, Hamadi Khemakhem, Annie Simon, Dominique Michau, et al.. Dielectric and ferroelectric properties of lead-free Ba_1−xLa_xTi_1−xFe_xO₃ ceramics. physica status solidi (a), 2011, 208 (1), pp.180-185. ⟨10.1002/pssa.201026083⟩. ⟨hal-00565839⟩