X-ray characterization of the new nasicon compositions Na3Zr2-x/4Si2-xP1+xO12 with x= 0.333, 0.667, 1.000, 1.333, 1.667

It is known that solids with composition Na3Zr2Si2PO12 heated at 1200°C crystallize in the nasicon structure. This material shows a high ionic conductivity that represents an interesting improvement in the field of solid electrolytes. Our experimental results allow to establish for the first time that nasicon structures are stable along the compositional join Na3Zr2-x/4Si2-xP1+xO12 with x extending from 0 to 1.667. These structures are characterized by a Zr underoccupation of octahedral sites and a constant number of Na+ ions. This fact envisages a possible application of these materials in the field of ceramic sensors and ionic conductors.