Preparation and characterization of polycrystalline La2Zr2O7 ultrafine fibres via electrospinning

Polyvinyl Pyrrolidone (PVP)/(Lanthanum nitrate and zirconium oxychloride) microfibres were fabricated by electrospinning. SEM micrographs indicated that the surface of the prepared composite microfibres was smooth, and the diameter of the microfibres was in the range of 2 microm-5 microm. X-ray diffractormetry (XRD) analysis revealed that the composite microfibres were amorphous in structure. La2Zr2O7 porous hollow ultrafine fibres (PHUF) were fabricated by calcination of the PVP/[La(NO3)3 + ZrOCl2] composite microfibres. The diameters of La2Zr2O7 PHUF were smaller than those of the PVP/[La(NO3)3 + ZrOCl2] composite microfibres. The surface of the ultrafine fibres became coarse with the increase of calcination temperatures. La2Zr2O7 PHUF formed by nanoparticles were acquired when calcination temperature was above 800 degrees C. Scanning electron microscope (SEM) analysis indicated that the diameter of the synthesized La2Zr2O7 PHUF was in the range of 500 nm-800 nm. XRD analysis revealed that the crystal structure of La2Zr2O7PHUF was found to be of the fluorite type when calcination temperature was 800 degrees C-900 degrees C, and of the pyrochlore type at 1000 degrees C. The latter is cubic in structure with space group Fd3m. The conductance of La2Zr2O7 PHUF is high to 5.19 S/cm2 and has no effect of frequency. Possible formation mechanism for La2Zr2O7 PHUF was preliminarily proposed.