Colossal permittivity and low losses in Ba1–xSrxTiO3–δ reduced nanoceramics. Issue 3 (February 2016)

• Record Type: Journal Article
• Authors: Dupuis, Sébastien; Sulekar, Soumitra; Kim, Ji Hyun; Han, Hyuksu; Dufour, Pascal; Tenailleau, Christophe; Nino, Juan Claudio; Guillemet-Fritsch, Sophie
• Is Part Of: Journal of the European Ceramic Society. Volume 36:Issue 3(2016)
• Page Start: 567
• Page End: 575
• Publication Date: 2016-02
• Subjects: Barium strontium titanate -- Colossal permittivity -- Spark plasma sintering -- Nanoceramic -- Dielectric properties; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.10.017
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The oxalate route offers a controlled approach to synthesize pure Ba1– x Sr x TiO3 (BST) (0 ≤ x ≤ 1) nanoparticles ( ϕ ≈ 150 nm in diameter). Reduced BST dense nanoceramics were obtained by spark plasma sintering (SPS) and then annealed for a short time to reach colossal permittivity ( ϵ ′ r = 10 5 ) with low dielectric losses (tan δ = 0.03) at 1 kHz and 300 K. The effects of Ba–Sr substitution on structural, microstructural and electrical properties were analyzed. Comprehensive analysis of the electrical properties indicates that polaron hopping, mediated by Ti 3+ ions and oxygen vacancies is the main contributing mechanism to colossal permittivity in Ba-rich BST compounds. Substitution of Ba by Sr reduced the contribution of polaron hopping and led to a decrease of real and imaginary parts of permittivity, while preserving interfacial polarization and yielding better temperature stability. The lowest temperature coefficient of capacitance, or TCC (variation of capacitance between 310 K and 450 K) value, i.e., 44 ppm K −1, is obtained for SrTiO3 .