Abstract: A dielectric ceramic composition for microwave use having a relative permittivity &egr;r of 35 to 45, Qf0 value of more than 50,000 GHz (at 7 GHz), and dielectric characteristic of &tgr;f=0±10 ppm/° C includes an La2O3.Al2O3.SrO.TiO2 based ceramic composition and a specific quantity of Ga2O3 to increase the Qf0 value and a specific amount of Pr2O3to control the &tgr;f value.

Abstract: An object of the present invention is to provide a dielectric ceramic composition for microwave use having a relative permittivity &egr;r of 35 to 45, Qf0 value of more than 50,000 GHz (at 7 GHz), and dielectric characteristic of &tgr;f=0±10 ppm/° C. In a La2O3.Al2O3.SrO, TiO2 based ceramic composition, by adding a specific quantity of Ga2O3 to this ceramic composition, the Qf0 value is increased and by further adding a specific amount of Pr2O3, it becomes possible to control the &tgr;f value.

Abstract: A method for producing X(BaZ.Sr1-Z)(Zn⅓.(TaM.Nb1-M)⅔)O3—Y(BaZ′.Sr1-Z′)(Ga½.Ta½)O3 solid solution system, characterized in that sintering is carried out at a temperature of 1400° C. to 1550° C. in an atmosphere of N2 containing oxygen in a concentration of 6% to 40% or sintering is carried out at a temperature of 1400° C. to 1550° C. after presintering at a temperature of 900° C. to 1300° C. This method is suitably used in order to constantly produce a dielectric porcelain composition for an electronic device which has a reduced temperature coefficient of resonance frequency and an excellent specific dielectric constant, and is uniform with respect to the quality distribution in one composition, by suppressing the evaporation of the Zn contained in a conventional porcelain composition of a perovskite type compound and adjusting the oxygen concentration in an atmosphere for sintering to a specific value without controlling a composition.

Abstract: A dielectric ceramic composition for electronic devices, which exhibits &tgr;f and ∈r characteristics equivalent or superior to those of the dielectric ceramic composition of the prior art, can inhibit the evaporation of Zn from the composition to thereby facilitate the control of makeup of the composition, can give homogeneous ceramics through short-time sintering more stably, is improved particularly in permittivity (Qf) and controllability of temperature characteristics, and permits downsizing of the dielectric elements. This composition is a solid solution of XBa(Zn⅓.Ta⅔)O3—Y(BaZ.Sr1−Z)(Ga½.Ta½)O3 which contains a specific trivalent metal ion and has a Zn content adjusted to a predetermined level, wherein part of Ta contained in the XBa(Zn⅓.Ta⅔)O3 moiety has been replaced by Nb. The composition is improved not only in permittivity by virtue of the above replacement but also in the degree of sintering by virtue of the above trivalent metal, i.e.