Effect of La substitution on structural and electrical properties of Ba(Fe2/3W1/3)O3 nanoceramics

• Published in: Journal of materials science 2007-09, Vol.42 (17), p.7423-7432
• Main Authors: Choudhary, R. N. P, Pradhan, Dillip K, Tirado, C. M, Bonilla, G. E, Katiyar, R. S
• Format: Article
• Language: English
• Subjects: Applied sciences; barium; Building materials. Ceramics. Glasses; Ceramic industries; ceramics; Chemical industry and chemicals; Composition; Dielectric properties; Dielectric strength; electrical conductivity; Electrical properties; Electrical resistivity; Electrotechnical and electronic ceramics; Exact sciences and technology; High temperature; impedance; Materials science; nanocrystals; ozone; Parameters; Permittivity; Perovskites; powders; Structural analysis; Substitution reactions; Technical ceramics; temperature; Temperature dependence; X-radiation
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-007-1835-z

The nanocrystalline fine powders (∼80 nm) of (Ba₁₋ₓ La ₓ)(Fe₂/₃W₁/₃)₁₋ₓ/₄O₃, (BLFW) (x = 0.0, 0.05, 0.10 and 0.15) were synthesized with a combined mechanical activation and conventional high-temperature solid-state reaction methods. Preliminary X-ray structural analysis of pellet samples (prepared from fine powders) showed formation of a single-phase tetragonal system. Detailed studies of dielectric properties (εᵣ and tan δ) exhibit that these parameters are strongly dependent on frequency, temperature and La composition. The La-substitution increases the dielectric constant and decreases the tan δ up to 10% substitutions of La at the Ba-site, and then reversed the variation, and hence this composition is considered as a critical composition. This observation was found valid for structure, microstructures, dielectric constant, electrical conductivity, J–E characteristics and impedance parameters also. Like in other perovskites (PZT, BZT), La substitution plays an important role in tailoring the properties of Ba(Fe₂/₃W₁/₃)O₃ ceramics.