Facile molten salt synthesis of zirconia whiskers

Abstract

ZrO2 whiskers have been synthesized by a facile molten salt method using ZrOCl2 · 8 H2O and Na3PO4 · 12 H2O as the zirconium source and molten salt, respectively. Differential thermal and thermogravimetric analyses, X-ray diffraction analysis, field emission scanning electron microscope and transmission electron microscope were employed to characterize the heating process of the precursor mixture, phase composition of the as-synthesized ZrO2 whiskers and the effect of reaction temperature on the synthesis of ZrO2 whiskers. The results show that the ZrO2 whiskers synthesized at 900 °C have an average aspect ratio of 30 and preferentially grow along [010] direction. The formation of sodium zirconium phosphate [Na9-4xZrx(PO4)3] (x = 1, 2) and the reaction temperature play an important role in the growth of ZrO2 whiskers. This work also suggests an effective route for mass production of high quality ZrO2 whiskers.

Keywords

• molten salt method
• zirconia whisker
• crystal growth
• sodium zirconium phosphate