Thermally crystallisable glass-ceramic - based on oxides of germanium, niobium, and alkali(ne earth) metals or lead

摘要

Glass-ceramic materials having high dielectric permeability (up to 1000 or even more, low dielectric loss (less than 2%), and high index of refraction (2.000) have one of the following compsns. (in mole %): (A) GeO2 30-40, Nb2O5 30-35, Na2O 30-35, Na2O:Nb2O5 = 0.8:1 TO 1.2:1; (B) GeO2 18-40, Nb2O5 25-45, Na2O + K2O and/or LiO2 25-45; Na2O:(K2O and/or Si2O) = 1:1 to 3:1; (C) GeO2 39-52, Nb2O5 27-41, SrO or BaO 16-26, Nb2O5: (SrO + BaO) = 1:3 to 2:1; or (D) GeO2 35-60, Nb2O5 19-35, PbO 16-35, NB2O3:PbO = 0.9:1 to 1.5:1. Nb2O5 can be partly replaced by Ta2O5. These materials can be used for the mfr. of condensers, insulators, dielectric parts for use in pointed microcircuits, electroluminescent devices, wave guides, etc.