Direct preparation of K0.5Na0.5NbO3 powders

✍ Scribed by Heng Jiang; Ting Ting Su; Hong Gong; Yu Chun Zhai

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 155 KB
• Volume: 46
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/crat.201000501

✦ Synopsis

Na 0.5 NbO 3 , solid-state method, direct preparation. K 0.5 Na 0.5 NbO 3 powders have been directly synthesized by an alternative solid-state method. Stoichimometric mixture of ammonium niobium oxalate and C 4 H 4 O 6 KNa•4H 2 O were calcined in temperature range from 500 to 800 °C for 3 h. The precursor and calcination products were characterized with respect to stoichiometry, purity, crystalline structure, particle size and powder morphology using X-ray diffraction (XRD), X-ray fluorescence (XRF) spectrometer, scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectra, thermogravimetric (TG) analysis, differential scanning calorimetry (DSC) and UV-Vis diffuse reflectance (UV-Vis) spectroscopy. XRD and XRF results reveal that stoichiometric K 0.5 Na 0.5 NbO 3 powders could be synthesized by the method. The particle size is about 68 nm for the precursor calcined at 500 °C according to XRD data, which is in good agreement with SEM data. The average band gap energy is estimated to be 3.18 eV by UV-vis diffuse reflectance spectra.