Synthesis of MgNb2O6 nanocrystalline powders by an improved citrate sol-gel technique

摘要

MgNb2O6 nanocrystalline powders have been synthesized at a low temperature by improved citrate sol-gel method in this paper. The high quality solution of Nb~(5+) was prepared using Nb2O5 as the starting material. The crystal structure and microstructure of MgNb2O6 powders were characterized by XRD and SEM techniques, and the effects of preparation craft including pH value and the proportion of citric acid to the niobium ions on the crystal structure and microstructure of powders were also investigated. XRD and TG/DTA results show that the single phase of MgNb2O6 for synthesized powders can be obtained by calcining the precursor at 700 °C. SEM results indicate that the average particle size of MgNb2O6 exhibits a significantly dependence on the pH values and the proportion of citric acid to the niobium ions, where it was found that particle size of a 20 nm can be obtained for the MgNb2O6 powders by sol-gel process.