Structural studies of NASICON material of different compositions by sol–gel method

The NASICON (Na1 + xZr2SixP3 − xO12) is a well known solid electrolyte material with high ionic conductivity. The ion conductivity can be improved by modifying the structure. The NASICON powders with different compositions (by varying x) have been prepared by sol–gel method. The structural and conductivity measurements have been done by XRD, complex plane impedance analysis and electrochemical cell method. The results indicate that the ac conductivity and Na+ ion selectivity are higher for x = 2.05 as compared to other compositions. The enhancement of Na+ ion conductivity for x = 2.05 has been attributed to modifications in the orientations of tetrahedral structures which lead to change in the bottleneck size. The results have been confirmed by X-ray diffraction (XRD).