Hydrothermal synthesis of NaNbO3-morphology change by starting compounds

Abstract

Perovskite-type sodium niobate, NaNbO3 was prepared by hydrothermal reaction using an amorphous hydrated niobium oxide (a-Nb 2O5). A single phase of perovskite-type NaNbO3 was obtained under the condition of 160°C and 1.0M NaOH solution, and at higher temperature (≥180°C) cubic shape particles with the size of 510μm were produced. These cubic shape particles had well developed 110 and 001 planes. When other starting compounds, Nb2O5, HNbO3·nH2O and HNb3O8· nH2O were used, well crystallized particles were not obtained. The particles prepared from HNbO3·nH2O and HNb 3O8·nH2O had irregular shape and cubic-like shape with the size of 15 μm. In the case of Nb2O 5 fine particles with the submicron size of ̃0.5μm were obtained. © 2011 The Ceramic Society of Japan.