New oxyfluoride lead-free ferroelectric relaxors in the BaTiO3-BaZrO3-BaLiF3 system

• Published in: Materials letters 2000, Vol.42 (3), p.189-193
• Main Authors: KERFAH, A, TAÏBI, K, GUEHRIA-LAÏDOUDI, A, SIMON, A, RAVEZ, J
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Niobates, titanates, tantalates, pzt ceramics, etc; Permittivity (dielectric function); Physics
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(99)00182-2

X-ray powder diffraction was used to determine the limits of solid solution in the ternary system BaTiO3-BaZrO3-BaLiF3. Dielectric measurements were performed in the frequency and temperature range 10 exp(2) to 2 x 10 exp(5) Hz and 77-450 K, respectively. This ternary system showed both classical ferroelectric and relaxor ferroelectric behaviours depending on the composition. The results were related to ionic substitution and chemical bonding. A spontaneous classical ferroelectric-relaxor ferroelectric transition was observed for the first time in a lead-free perovskite-type phase. These compositions are of interest for applications (dielectrics for capacitors, actuators) since they are environment-friendly. 11 refs.