Synthesis and characterization of nano scale YTiNbO6 – Energy material

Abstract

Nano particles of YTiNbO6 are synthesized through a modified combustion technique. The compound have been studied for their properties and characterized structurally, optically and electrically. Phase purity, crystal structure and particle size of the nano powder are examined using X-Ray diffraction, FT Raman and transmission electron microscopic techniques. The X-Ray diffraction study reveals that the nanoparticles of YTiNbO6 ceramics crystallize in orthorhombic euxenite structure. The Structure is also confirmed by using FT Raman spectroscopic technique. The samples show a relatively narrow size and in nano size is observed in TEM which is good agreement with the result obtained from the XRD analysis. The absorption coefficient near the fundamental edge depends on the photon energy and it obeys the Tauc’s equation. The optical band gap is obtained as 2.43 eV. The sintering temperature of the nanocrystalline powder is found to be reduced by about 150 °C when compared to the other method of preparation. This is due to the high surface to volume ratio of the nano particles. It is also evident from the SEM that the sample has achieved high densification with little porosity. The impedance plot can be deconvolute into three semicircles indicating the contribution of grain and grain boundary conduction. The depressed semicircle suggests that the departure from the ideal Debye behavior. Highest ionic conductivity is observed for the nano scale YTiNbO6. These materials can be made useful in solid oxide fuel cells and in opto electronic devices.