Na+-superionic conductors of glass–ceramics in the system Na2O–Sm2O3–X2O3–P2O5–SiO2 (X=Al, Ga)

Glass–ceramics of the aluminum or gallium, and phosphorus-containing Na5SmSi4O12-type Na+-superionic conductors (N5SXPS) were prepared by crystallization of glasses with the composition Na3+3x−y+zSm1−xXzPySi3−y−zO9 (X=Al; NSAPS, X=Ga; NSGPS), and the effects of X elements on the separation of the phase and the microstructural effects on the conduction properties of glass–ceramics were discussed. N5SXPS was obtained as a stable phase at high temperatures. The ionic conductivities of NSAPS and NSGPS were 0.67×10−1 and 0.76×10−1 S/cm at 300 °C, respectively.