Numerical study on dielectric permittivity for the ferroelectric ceramic with composition KTa_0.6Nb_0.4O₃

I. Kriaa (1) , Najmeddine Abdelmoula (1) , A. Maalej (1) , Hamadi Khemakhem (1) , Annie Simon (2) , Jean Ravez (2)

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

Based on the Debye theory, we have determined the evolution of the dielectric permittivity of the ceramic with composition KTa_0.6Nb_0.4O₃ as a function of temperature and frequency. This evolution shows that this composition exhibits a ferroelectric–paraelectric phase transition at 360 K with dispersion at high frequencies (10⁶–6 × 10⁸ Hz). A comparison between experimental and numeric calculation of dielectric permittivity for this solid solution has been suggested using a Gaussian distribution of the relaxation times, which was introduced in Debye relations. The numerical results were in agreement with experimental data.

Mots clés: Ceramics; Perovskite; Dielectric; Debye theory; Ferroelectric

Domaines: Matériaux

I. Kriaa, Najmeddine Abdelmoula, A. Maalej, Hamadi Khemakhem, Annie Simon, et al.. Numerical study on dielectric permittivity for the ferroelectric ceramic with composition KTa_0.6Nb_0.4O₃. Journal of Alloys and Compounds, 2010, 508 (2), pp.453-456. ⟨10.1016/j.jallcom.2010.08.092⟩. ⟨hal-00545049⟩