Defect structure and morphology of alkali niobate (Na0.5K 0.5)NbO3 powder calcined under low oxygen partial pressure

Keisuke Kobayashi, Hiroyuki Shimizu, Yutaka Doshida, Youichi Mizuno, Clive A. Randall

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3 Scopus citations


The effects of oxygen partial pressure (pO2) in the calcination process of perovskite (Na0.5K0.5)NbO3 (NKN) are investigated in terms of morphology and defect structure. Ceramic powders calcined in low-pO2 atmospheres exhibit cubic-shaped particles with smaller mean diameter. The tail of the absorption edge in UV-visible diffuse reflectance spectra becomes smaller at low-pO2 atmospheres in the calcination process, implying the suppression of alkali vacancies. The smaller powder size and lower concentration of alkali vacancies in low-pO 2-calcined powder improves the sinterability, thereby leading to higher resistivity. Therefore, the low-pO2 calcination is an essential process for NKN-based piezoelectrics.

Original languageEnglish (US)
Article number101502
JournalApplied Physics Express
Issue number10
StatePublished - Oct 2013

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Physics and Astronomy(all)

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