From normal ferroelectric transition to relaxor behavior in Aurivillius ferroelectric ceramics
Résumé
The influence of the barium concentration on the dielectric response of Sr1−x Ba x Bi2Nb2O9 system, with x = 0, 15, 30, 50, 70, 85, 100 at.%, has been studied. The barium concentration dependence of T m, as well as the temperature of the corresponding maximum for the real part of the dielectric permittivity, has suggested a cation site mixing among atomic positions, which has been supported by the structural analysis. A transition from normal ferroelectric–paraelectric phase transition to a relaxor behavior has been observed in the studied samples, when the barium concentration has increased. The relaxor behavior has been discussed.