Investigation of dielectric relaxation processes in Ba2NdFeNb4-xTaxO15 ceramics

Martynas Kinka (1) , D. Gabrielaitis (1) , Marjorie Albino (2) , Michaël Josse (2) , E. Palaimiene (1) , Robertas Grigalaitis (1) , Mario Maglione (2) , Juras Banys (1)

1 Faculty of Physics [Vilnius]
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Dielectric response of Ba2NdFeNb4-xTaxO15 (x = 0.3, 0.6 and 2) solid solutions with Tetragonal Tungsten Bronze structure has been investigated by means of broadband dielectric spectroscopy in the frequency range from 20 Hz to 37 GHz. Pure Ba2NdFeNb4O15 compound displays ferroelectric behavior. Substitution of Nb5+ by Ta5+ considerably alters dielectric response of this system. Ferroelectric state was observed only for x = 0.3 compound with slightly lowered ferroelectric phase transition temperature. Further increase of x causes formation of relaxor state in these solid solutions and considerably lowers corresponding dielectric permittivity dispersion temperature region.

Mots clés: Tetragonal tungsten bronze; broadband dielectric spectrosopy; ferroelec trics; ferroelectric relaxor; dielectric relaxation

Domaines: Matériaux

Martynas Kinka, D. Gabrielaitis, Marjorie Albino, Michaël Josse, E. Palaimiene, et al.. Investigation of dielectric relaxation processes in Ba2NdFeNb4-xTaxO15 ceramics. Ferroelectrics, 2015, 485 (1), pp.101-109. ⟨10.1080/00150193.2015.1061348⟩. ⟨hal-01239694⟩