Preparation and Properties of Quenched Li 2 O‐BaO‐Nb 2 O 5 Glasses

Glasses were prepared in the wide variety of compositions in the system Li 2 O‐BaO‐Nb 2 O 5 , which contains no “glass‐former,” by the twin‐roller quenching technique. The crystallization temperature ranges from 500° to 700°C and increases as Li 2 O is replaced by BaO. The dielectric constant increases steeply with temperature, reaching an anomalously large value (10 4 ) in glasses which contain a large amount of Li 2 O. Such a temperature dependence of dielectric constant is very similar to that of conductivity in each glass, indicating that the dielectric behavior is caused by polarization due to the ionic motion in glass. The conductivity at 500 K ranges from 10 −13 to 10 −5 Ω −1 ·cm −1 and the activation energy for conduction from 120 to 40 kJ/mol. The concentration of Li + ions mainly controls the conductivity and the addition of Ba 2+ ions slightly lowers it.