Preparation of LiNbO 3 powder from the thermal decomposition of a precursor salt obtained by an evaporative method

The preparation of lithium niobate powder, LiNbO3, using an organic niobium salt and lithium nitrate in a buffer solution of oxalic acid and ammonium oxalate has been investigated. After the evaporation of this starting solution a precursor is obtained, which upon heat treatment, yields LiNbO3. A chemical formula for this precursor is proposed, based on IR and thermal analysis data. The thermal evolution of the precursor powder, to the point of the formation of the LiNbO3 phase, was followed by means of thermal analysis, IR spectroscopy and powder X-ray diffraction (XRD). The results indicate that total crystallization occurs after a 550 °C heat treatment, showing that single-phase LiNbO3 powder, with a crystallite mean size of 88 nm, can be prepared at low processing temperatures.