Low-temperature synthesis of bismuth titanate by modified citrate amorphous method

Author(s)

Tinti, V. B. ^{[1, 2]} ; Marani, D. ^[1] ; Kabir, A. ^[2] ; Haugen, A. B. ^[2] ; Esposito, V. ^[2] ; de Florio, D. Z. ^[1]

Affiliation

^[1] Fed Univ ABC UFABC, Modelling & Appl Social Sci Ctr CECS, Ave Estados 5001, BR-09210580 Santo Andre, SP - Brazil

^[2] Tech Univ Denmark DTU, Dept Energy Convers & Storage, Fys Vej, Bldg 310, DK-2800 Lyngby - Denmark

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 47, n. 9, p. 12130-12136, MAY 1 2021.
• Web of Science Citations: 0

Abstract

Bismuth titanate is a lead-free piezoelectric ceramic with outstanding properties that strictly depend on the composition and microstructure. However, bismuth-based materials are difficult to synthesize due to bismuth volatilisation that causes secondary phases and stoichiometry deviations. In this work, we propose a lowtemperature chemical route, i.e. a modified amorphous citrate method, that allows a reduction of thermal treatment temperature, when compared with solid-state or other chemical routes, to obtain single-phase bismuth titanate samples. Single-phase powders with particle size under 300 nm are produced by calcination at 700 ?C, and prepared into homogeneous dense pellets (density above 95%), with only isolated pores. The pellets show two distinctive features in the electrical behaviours directly associated with their mica-like microstructure: planar oriented boundaries are responsible for oxygen conduction, while the bulk is dominated by electronic conductivity. The samples show a high dielectric constant, around 200 at room temperature, while maintaining a low loss factor. The pellets also achieved a maximum polarisation of 5.85 ?C/cm2 and an inverse piezoelectric coefficient of 7.4 pm/V. The dielectric and piezoelectric properties obtained are comparable or superior to the state-of-the-art. (AU)

• FAPESP's process: 15/24999-2 - New ceramic compounds for protonic solid oxide fuel cells
• Grantee: Daniel Zanetti de Florio
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/11937-4 - A sustainable path to methane conversion by advanced electrochemical technologies
• Grantee: Fabio Coral Fonseca
• Support Opportunities: Research Grants - Research Centers in Engineering Program