  The high ionic conducting sodium superionic conductor Na3Zr2Si2PO12 -NaI
composites have been prepared successfully via solid state reaction route. As
the NaI content increases, the ionic conductivity significantly changes. The
composites with 4% NaI show a maximum ionic conductivity of ~ 3 x 10-4
{\Omega}-1cm-1 at 200oC which is one order of magnitude rise as compared to
pristine sample. Further crystal structure and surface morphology also reveal
the formation of a glassy phase due to the presence of Na-Si-P-O-I interaction.
