Strontium titanate-bismuth-titanium oxide ceramic dielectric - contg alkali metal oxide, giving high dielectric constant and low loss

摘要

A ceramic dielectric compsn., contg. SrTiO3, Bi2O3 and TiO2 as first component (I), contains 35-93.5 wt% SrTiO3, 4-40 wt% Bi2O3 and 2.5-60 wt% TiO2, w.r.t. the total wt. of (I), and, as second component (II), 0.1-5.0 wt% oxide(s) of Li, Na, K, Rb and/or Cs, w.r.t. the total wt. of (I). It opt. also contains, as third component (III), a smaller but effective amt. of (a) oxide(s) of Mn, Cr, Fe, Co, Ni, Nb and/or Ta, (b) clay and/or (c) oxide(s) of rare earths, e.g. La and/or Ce. Up to 30 wt% of the SrO can be replaced by oxide(s) of Ca, Zn, Mg, Be, Ba, Cd and/or Pb and 30 wt% of the TiO2 by oxide(s) of Zr, Sn and/or Hf. The compsn. is used in vacuum or gas circuit breakers, mountings or ceramic ducts, transmission systems, potentiometers, voltage-multiplying rectifiers in TV receivers and oscilloscopes etc. The compsn. has a high dielectric constant and low loss, which show little variation over a wide range of alternating and direct voltages.