Synthesis of piezoelectric and bioactive NaNbO3 from metallic niobium and niobium oxide.

Abstract

NaNbO3 was synthesized by two different routes, one using metallic niobium powder, and another using niobium oxide (Nb2 O5 ) powder. In both routes an aqueous sodium hydroxide solution was used to hydrothermally treating the powders. In the first approach, the solution concentrations were 3M, 1M, and 0.5M. The second route used solution concentrations of 10M and 12.5M. After the hydrothermal treatments, the powders were heat treated in order to synthesize NaNbO3 . The products were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) with Rietveld refinement. The phases were identified by means of X-ray diffraction (XRD) with Rietveld refinement. It was observed that the molar concentrations of the solutions had opposing effects for each route. An antiferroelectric phase was found in both routes. In the niobium metallic route, a ferroelectric phase was also synthesized. This study proves that piezoelectric NaNbO3 can be obtained after alkali treatment of both Nb and Nb2 O5. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 979-985, 2016.