Glass–ceramics of the Al or Ga, and P-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 considered. N5SXPS was obtained as a stable phase at high temperatures. The ionic conductivities of NSAPS and NSGPS were 0.67 x 10−1 and 0.76 x 10−1S/cm at 300C, respectively.

Na+-Superionic Conductors of Glass–Ceramics in the System, Na2O–Sm2O3–X2O3–P2O5–SiO2 (X = Al, Ga). T.Okura, H.Monma, K.Yamashita: Solid State Ionics, 2004, 172[1-4], 561-4