A Calcination Technology for Ultrafine La3NbO7 Powder Prepared by Sol-Gel Process

In order to prepare ultrafine La3NbO7 powder, a potential material for thermal barrier coatings, the calcination process of La3NbO7 was studied in this paper.The precursor of La3NbO7 was synthesized by using a citric acid complex method. A calcination process had been systematically investigated. The reaction temperature was determined by differential scanning calorimetry(DSC). The phase composition of powders was characterized by X-ray diffraction(XRD), and the morphology was obtained by scanning electron microscope (SEM). The results revealed that the single-phase La3NbO7 powder could be successfully prepared while the calcination temperature exceeded 800 degrees C and a better morphology could be maintained at 800 degrees C for 4 hours. Considering all above, an optimum calcination scheme was adopted at 800 degrees C for 4 hours. The as-prepared La3NbO7 powders had a grain size of about 50nm and an average particle size of about 300nm.