Divalent Magnesium Ionic Conduction in Mg[sub 1−2x](Zr[sub 1−x]Nb[sub x])[sub 4]P[sub 6]O[sub 24 ](x=0–0.4) Solid Solutions

A high ion‐conducting phosphate‐based solid electrolyte with a solid solution form was synthesized by substituting the tetravalent site in for a pentavalent . Because of the replacement, the activation energy for ion migration became considerably low compared with that for the mother phase of and an appreciable enhancement of ion conductivity was observed especially in a relatively low‐temperature region. The site substitution in for makes for a superior effect on the stabilization of the high‐temperature phase of . A successful formation of the above mentioned solid solution results in the statistical distribution of mobile ion in three sites occupied by mobile and contributes greatly to making a smooth ion migration in the solid solution.