Synthesis of nanocrystalline barium titanate: Effect of microwave power on phase evolution

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • Loughborough University
  • Currently at School of Metallurgy and Materials

Abstract

Nanocrystalline BaTiO3 (BT) powder was synthesised using a polymer precursor route and the influence of conventional, microwave and combined hybrid heating methods on phase formation was investigated. A single-phase tetragonal BT (t-BT) nanocrystalline powder of about 20 nm primary particle size and decreased agglomeration were formed when high levels of microwave energy were used. This was accomplished at a lower processing condition of 700 °C for 30 min compared to conventional processing, which required 900 °C for 5 h, resulting in potential savings in time and energy. During the nano BT synthesis, the role of microwaves was determined by subjecting the samples to identical thermal histories, i.e. exactly the same time-temperature profiles, while using a range of different levels of microwave power. Significant reduction in the activation energy for the formation of the tetragonal phase was observed with increasing levels of microwave power and the results are explained in terms of a possible non-thermal mechanism. Furthermore, under otherwise identical thermodynamic conditions of temperature, time and (atmospheric) pressure, the co-occurrence of hexagonal crystal structure at < 200 W of additional microwave power along with formation of tetragonal crystal structure at ≥ 200 W and single phase tetragonal crystal structure at ∼1200 W was observed, demonstrating a new method of controlling the phase evolution during the synthesis of nanostructured barium titanate powder. The methodology could be applied to synthesise a variety of functional ceramic powders with tailored levels of crystallographic phases.

Bibliographic note

Funding Information: The authors thank Loughborough University for sponsoring the PhD studentship for Vinothini Venkatachalam and Loughborough Materials Characterisation Centre (LMCC) for their support with the structural and microstructural investigations. The Engineering Physical Sciences Research Council (EPSRC) is thanked for funding support (Grant No: TS/G000891/1 ). Funding Information: The authors thank Loughborough University for sponsoring the PhD studentship for Vinothini Venkatachalam and Loughborough Materials Characterisation Centre (LMCC) for their support with the structural and microstructural investigations. The Engineering Physical Sciences Research Council (EPSRC) is thanked for funding support (Grant No:TS/G000891/1). Publisher Copyright: © 2020 Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

Details

Original languageEnglish
Pages (from-to)3974-3983
Number of pages10
JournalJournal of the European Ceramic Society
Volume40
Issue number12
Publication statusPublished - Sep 2020

Keywords

  • Barium titanate, Mechanism, Microwave processing, Raman spectroscopy, Synthesis