Structural and electrical properties of superionic NaXZO(6) (X = Nb, Ta; Z= Mo, W) ceramics

Superionic or proton conductors exhibit very high ionic conductivity at or above room temperature with negligibly small electronic conductivity. Alkal i ion conductors play an important role in the family of superionics. In th is context polycrystalline NaXZO(6) (X = Nb, Ta; Z = Mo, W) samples were st udied. X-ray diffraction (XRD) studies reveal that all the samples have ort horhombic structure at room temperature. The dielectric (constant and loss) studies are carried out in the wide range of frequency (10(3)-10(6) Hz) an d temperature (300-600 K). The ionic character of the compounds is checked by dc resistivity and transference number measurements.