Synthesis of Na2O-RE2O3-SiO2 (RE = Sm, Gd, Dy, Y, Ho, Er and Yb) system glasses and their electrical properties

Seven kinds of sodium rare-earth silicate glass, (Na2O)(35.7)(RE2O3) (7.2)(SiO2)(57.1)(RE = Sm, Gd, Dy, P, Ho, Er and Yb), were synthesized by melting a mixture of Na2CO3, RE2O3 and SiO2 and their electrical properties were investigated, The densities of glasses were in fairly good agreement with the theoretical densities predicated for Na5RESi4O12 ceramics, The crystallization temperature and the crystal melting temperature linearly decreased with increasing the ionic radius of RE. The highest electrical conductivity at 200 degrees C (1.55 x 10(-4) S . cm(-1)) was achieved for (Na2O)(35.7)(Yb2O3)(7.2) (SiO2)(57.1) The electrical conductivity slightly decreased with increasing the ionic radius of RE.