Conductivity measurements on nasicon and nasicon-modified materials (CAT#: STEM-PPA-0028-WXH)

Introduction

NASICON is an acronym for sodium superionic conductors of the general formula AnB2(PO4)3, where B is generally a TM ion or elements like Zr, Ge, Sn, etc.
The crystal structure of NASICON compounds was characterized in 1968. It is a covalent network consisting of ZrO6 octahedra and PO4/SiO4 tetrahedra that share common corners. Sodium ions are located at two types of interstitial positions. They move among those sites through bottlenecks, whose size, and thus the NASICON electrical conductivity, depends on the NASICON composition, on the site occupancy, and on the oxygen content in the surrounding atmosphere. The conductivity decreases for x < 2 or when all Si is substituted for P in the crystal lattice (and vice versa); it can be increased by adding a rare-earth compound to NASICON, such as yttria.