Effect of crystallite size on the low-temperature solid-solid phase transformations in the WO3 system

Owen O. Abe, Zanlin Qiu, Zexu Chen, Joerg R. Jinschek, Pelagia Irene Gouma*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Ferroelectric nanostructured ε phase tungsten trioxide (ε-WO3) is emerging as an important functional material with unique gas sensing and optoelectronic properties. However, ε-WO3 phase is typically unstable in the bulk at room temperature (RT) and it has only been produced at ambient conditions by rapid solidification processes, such as Flame Spray Pyrolysis (FSP). This work aims to assess the overall stability of the ε phase at the nanoscale by studying its transformation from the stable γ phase to upon cooling. In-situ Raman spectroscopy has explored the effect of crystallite size on the solid-solid phase transformation from the symmetric γ (monoclinic) phase into the acentric ε (monoclinic) phase. The phase transformation onset temperature (Tonset) ranges from −43 °C for bulk state to −150 °C for crystallites of 68 nm in size and varies linearly with the inverse of the crystallite size radius (1/r).

Original languageEnglish
JournalCeramics International
Volume47
Issue number23
Pages (from-to)33476-33482
ISSN0272-8842
DOIs
Publication statusPublished - 2021

Keywords

  • Ferroelectrics
  • Metal oxide
  • Phase transformation
  • Raman spectroscopy
  • Tungsten trioxide

Fingerprint

Dive into the research topics of 'Effect of crystallite size on the low-temperature solid-solid phase transformations in the WO<sub>3</sub> system'. Together they form a unique fingerprint.

Cite this