Abstract :
Ba[(Fe0.5Nb0.5)1−xTix]O3 ( x = 0.2 , 0.4 , 0.6 , 0.8 , 0.85 , 0.9 and 0.95) solid solutions were synthesized by a standard solid-state reaction technique. X-ray diffraction at room temperature and dielectric characteristics over a broad temperature and frequency range were evaluated systematically. The structure of Ba[(Fe0.5Nb0.5)1−xTix]O3 solid solutions changed from cubic to tetragonal with increasing x . A Debye-like dielectric relaxation following the Arrhenius law similar to that in Ba(Fe0.5Nb0.5)O3 was observed at lower temperature in the composition range 0.2 ≤ x ≤ 0.8 , while the relaxor ferroelectric, diffused ferroelectric and normal ferroelectric behavior were observed for x = 0.85 , 0.9 and 0.95, respectively. The process of the evolution of relaxor-like dielectric to ferroelectric suggested the changing from dilute polar micro-domains to polar micro-domains, polar micro/macro-domains and then polar macro-domains in the present ceramics.
