Abstract
Various Narpsios consisting of the composition formula of Na3+3x-yR1-xPySi3-yO9(R: rare earth, In and Sc) were synthesized by the crystallization of a glass. The formation of Narpsio-V having high conduction property was influenced by the kind of R element. The specimens with single phase of Narpsio-V were obtained in the use of Sm, Eu, Gd, Y and Er. In particular, the Narpsio-V widely yielded on the composition map of [Y] vs. [P]. The R elements also affected the conduction properties. The activation energy for Na+ conduction in Narpsio-V was improved with increasing the ionic radius of R element. Although the lowest activation energy was confirmed in the case of Sm, the total conductivity of whole specimen with Sm was lower than that with Gd. This was due to the difference in the grain boundary.
