“…Data on the properties of sodium-yttrium-silicate glasses in the literature is scarce [15][16][17]. On the basis of glass studies with different content of Li 2 O, Na 2 O, Y 2 O 3 and SiO 2, Alexander and Riley [15] assumed that the most optimal ratio in terms of glass conductivity is Na 2 O/Y 2 O 3 = 6.5.…”