Ionic Conductivity of the NASICON-Related Thiophosphate Na Ti Ga (PS ).

Inspired by the recent interest in fast ionic conducting solids for electrolytes, the ionic conductivity of a novel ionic conductor Na Ti Ga (PS ) has been investigated. Using X-ray diffraction and impedance spectroscopy the sodium ionic conductivity in this compound was demonstrated, in which bond valence sum analysis suggests a tunnel diffusion for Na . Substitution with Ga leads to an increasing Na content, an expansion of the lattice and an increasing conductivity with increasing x in Na Ti Ga (PS ) . Given the relation to the NASICON family, upon replacement of the phosphate by a thiophosphate group, a rich structural chemistry can be expected in this class of materials. This work demonstrates the potential for making NaTi (PS ) an ideal system to study structure-property relationships in ionic conductors.