Preparation and characterization of ceramic nanofibers based on lanthanum tantalates

This paper is focused on a modified sol-gel synthesis of polymeric complex and controlled assembly of inorganic nanofibers based on perovskite lanthanum tantalate La1/3TaO3 (LT) first time prepared by needleless electrospinning method. One advantage of the electrospinning method implementing PVA/LT polymer solution and subsequent thermal treatment provides a controlled patterning of the LT ceramic nanofibers. The structural properties and morphology of the composite PVA/LT were characterized by X-ray diffraction (XRD), differential scanning calorimetry/thermogravimetric analysis, Raman spectroscopy and scanning and transmission electron (SEM and TEM) microscopy. The surface microstructures of composite PVA/LT fibers were smooth, and their diameters were higher (about 100-200 nm) than those of the LT nanofibers. The mechanism of phase transformation from amorphous La4.67Ta22O62 at 400 A degrees C via pyrochlore LaTa7O19 to perovskite La1/3TaO3 at 900 A degrees C was determined. XRD analysis verified the formation of the major tetragonal La1/3TaO3 and minor orthorhombic LaTa7O19 phases at 1100 A degrees C. [GRAPHICS]