New relaxor ceramic with composition BaTi1-x(Zn1/3Nb2/3)xO3
Résumé
New ferroelectric ceramics of ABO3 perovskite type were synthesized in the BaTi1-x(Zn1/3Nb2/3)xO3 system by solid state reaction technique. The effect of the replacement of titanium by zinc (Zn) and niobium (Nb) in the B cationic site on structural and dielectric properties were investigated. As a function of composition, these compounds crystallize with tetragonal or cubic symmetry. The material is classical ferroelectric for 0 ≤ x ≤ 0.05 and presents a relaxor behavior for 0.075 ≤ x ≤ 0.2 and for 0.75 ≤ x ≤ 0.975. Dielectric permittivity in the temperature range from 85 to 500 K with frequencies range from 0.1 to 200 kHz, was studied. In the region when 0.75 ≤ x ≤ 0.975, ΔTm presents the important values which go more then 100 K for BaTi0.05(Zn1/3Nb2/3)0.95O3 composition with values of Tm near room temperature. These values make these ceramic compositions in the families of relaxors with interest properties for applications. © 2007 Elsevier B.V. All rights reserved.