Ionic conductivities of Na +-ion implanted silico–phosphate glass-ceramics

Abstract

Glass-ceramics of the phosphorus containing Na 5RSi 4O 12-type (R=rare earth) Na +-superionic conductors (Narpsio-V) in the systems Na 2O–Y 2O 3–P 2O 5–SiO 2 and Na 2O–Sm 2O 3–P 2O 5–SiO 2 were prepared by crystallization of glasses. The optimum conditions for crystallization are discussed with respect to the conduction properties and the preparation of uncracked glass-ceramic Narpsio-V. Large enhancement of electrical conductivity has been observed in the glass-ceramics by ion implantation of Na + ions at 200 keV with a flux density of 10 15 ions/cm 2. Upon this implantation the ionic conductivity of the glass-ceramic Na 3.9Y 0.6P 0.3Si 2.7O 9 and Na 3.9Sm 0.6P 0.3Si 2.7O 9 at 300°C is drastically increased from 2.01×10 −2 to 5.86×10 −2 S/cm and from 2.38×10 −2 to 7.15×10 −2 S/cm, respectively.