Novel and simple way to synthesize Na2Ti6O13 nanoparticles by sonochemical method

Solid state electrolytes based on ionic conductive ceramics, such as: the sodium titanate family, are promissory for secondary batteries. Thus, in this work, we reported for the first time, the synthesis of the Na₂Ti₆O₁₃ nanocrystals phase by using sonochemical method. X-ray diffraction and scanning electron microscopic techniques were employed to analyze the crystalline phases and the microstructure of the sintered samples. The ionic conductivity of the materials was measured by AC impedance spectroscopy. Complex Power was used to calculate the relaxation time constant. According to the X-ray patterns analysis, all nanocrystals synthesized by sonochemical method exhibited a pure monoclinic structure, which was confirmed by Rietveld refinement, with lattice parameters a = 15.12 (56) Å , b = 3.74 (40) Å , c = 9.17 (02) Å and V = 512.42 (4) ų and crystallite size - Dbar_hkl = 44.832 (55) nm. Calculated grain and the grain boundary room temperature conductivities were 2.93 × 10^-6 S/cm and 8.08 × 10^-7 S/cm, respectively. A significantly small relaxation time constant value of 26 μs was obtained for the Na₂Ti₆O₁₃ prepared sample. These results suggest that the material can be considered for electronic applications, such as: solid state electrolyte for batteries, from the fact that it allows a rapid percolation of ions through the structure.