Preparation, characterization and formation mechanism of single-crystal zirconia micro-sheets

Abstract

Zirconia micro-sheets were prepared by molten salt method using the salt mixture of NaCl and NaF. FE-SEM, TEM, EDS, DTA-TG, XRD, Raman and FT-IR techniques were employed to characterize the morphology, phase composition and formation mechanism of the ZrO2 micro-sheets. The obtained monoclinic ZrO2 microsheets with exposed {100} facets show an average thickness of 0.2 µm. The growth of the ZrO2 micro-sheets is proved to be assisted by the addition of fluoride. On the one hand, the addition of fluoride promotes the mass transfer of zirconia through the formation of zirconium fluoride complexes (ZrF 3 – 7). On the other hand, fluoride adsorbed on the surface of zirconia stabilizes {100} facets and lead to the exposure of {100} facets in the final product.

Keywords

• zirconia micro-sheet
• molten salt method
• fluoride
• crystal growth