Preparation of nanocrystalline lithium niobate powders at low temperature

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

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 173 KB
• Volume: 45
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/crat.201000105

✦ Synopsis

A facile route to prepare lithium niobate (LiNbO 3 ) powders was proposed by an alternative solid-state method. Stoichiometric Li 2 C 2 O 4 and ammonium niobium oxalate were mixed with small amounts of water and then dried at room temperature. It was demonstrated that Li[NbO(C 2 O 4 ) 2 ]•nH 2 O intermediate was produced by an ion-exchange reaction. Pure LiNbO 3 powders were successfully synthesized by heating the intermediate at 500, 600 and 700 °C for 3 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, UV-Vis diffuse reflectance (UV-Vis) spectroscopy and thermogravimetric (TG) analysis were used to characterize the precursor compound and as-prepared samples. XRD results reveal that all the products are identified as hexagonal structure with high relative crystallinity (>87%). The particle size is found to be about 40 nm for the mixture calcined at 500 °C according to XRD data, which is in good agreement with SEM data. The as-prepared LiNbO 3 powders by this method are high quality according to FTIR spectra. (Li 0.996 Nb 0.005 )Nb 0.999 O 3 phase was formed when the calcination temperature was raised to 800 °C.