Synthesis of potassium sodium niobate powders using an EDTA/citrate complexing sol-gel method

Yang Cao, Kongjun Zhu, Hongjuan Zheng, Jinhao Qiu, Honghui Gu

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

Potassium sodium niobate (KNN) powders were synthesized by a modified sol-gel method, using as starting chemicals potassium carbonate, sodium carbonate, and niobium hydroxide, and, as esterification and chelating agents, respectively, ethylene glycol (EG) and ethylene diamine tetraacetic acid (EDTA)/citrate. The effects of citric acid (CA), EG, and EDTA on the stability of the precursor sol were systemically investigated. The powders and gels were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC). The results indicated that a stable precursor sol was formed when n(CA):n(Mn+) = 3:1, n(EDTA):n(NH4OH) = 1:3.5, and n(CA):n(EG) = 1:2. The xerogel was calcined at 500-950 °C to prepare the KNN powder. Pure KNN perovskite phase with a cube-like structure was synthesized at 850 °C from the precursor sol for a K/Na molar ratio of 1.2. The formation mechanism of the KNN perovskite phase was also discussed.

Original languageEnglish
Pages (from-to)777-782
Number of pages6
JournalParticuology
Volume10
Issue number6
DOIs
Publication statusPublished - 2012 Dec 1
Externally publishedYes

Keywords

  • (KNa)NbO
  • EDTA/citrate
  • Sol-gel
  • Submicron powder

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Materials Science(all)

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