Electrical properties of (K2O)35.7 (RE2O3)7.2 (SiO2)57.1 (RE = Sm, Gd, Dy, Ho, Y, Er, Yb) glasses

Seven kinds of potassium rare earth silicate glasses, (K2O) (35.7) (RE2O3) (7.2) (SiO2) (57.1) (RE = Sm, Gd, Dy, Ho, Y, Er, Yb), were prepared by melting a mixture of K2CO3, RE2O3 and SiO2. Density increased with increasing atomic weight of RE. An exothermic peak attributable to crystallization was observed in the range between 720 and 800degreesC. Powder X-ray diffraction analysis showed the formation of two distinct phases, KREO2 and K2SiO3, above crystallization temperature. The conductivity of (K2O) (35.7) (Y2O3) (7.2) (SiO2) (57.1) glass was similar to those of K5YSi4O12 ceramics with the same composition and (K2O) (36) (SiO2) (64) glass not containing Y2O3.