Sintering, microstructures and dielectric properties of Ba_1-x Pb_x(Ti_1-xLi_x)O_3-3x F_3x ferroelectric ceramics

Laldja Taïbi-Benziadaa (1) , Annie Simon (2)

1 Institute of Chemistry
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Various compositions (1-x)BaTiO₃ + xPbF2+ xLiF were prepared, shaped to pellets then sintered at 900°C for 2 h in gold sealed tubes. The purity and the symmetry of the obtained samples were checked by X-ray diffraction. A new solid solution with Ba_1-x Pb_x(Ti_1-xLi_x) O_3-3x F_3x formula occurs in the composition range 0 ≥ x ≥ 0.20. SEM observations were performed on polished and fractured ceramics. The complex permittivity was measured as a function of temperature (-120°C ≥ T ≥ 250°C) and frequency (50 Hz ≥ f ≥ 4 × 10⁷ Hz). The dielectric performances are the best for ceramic Ba_0.97Pb_0.03(Ti_0.97 Li_0.03)O_2.91F_0.09. The real component ε'_r, exhibits a maximum of approximately 7500 at the ferroelectric Curie temperature T_C ≈ -18°C, the dielectric losses tan δ value being 0.012. At room temperature, the relaxation frequency f_r is around 40 MHz for this ceramic. This novel ferroelectric oxifluoride is a promising material for applications, in particular in the field of Z5U multilayer capacitors.

Mots clés: BaTiO₃; Dielectric properties; Oxifluoride; Sintering

Domaines: Matériaux

Laldja Taïbi-Benziadaa, Annie Simon. Sintering, microstructures and dielectric properties of Ba_1-x Pb_x(Ti_1-xLi_x)O_3-3x F_3x ferroelectric ceramics. Central European Journal of Chemistry, 2009, 7 (2), pp.159-163. ⟨10.2478/s11532-008-0063-y⟩. ⟨hal-00382794⟩