Abstract: The invention intends to provide a dielectric porcelain composition for use in electronic devices, in which the relative dielectric constant ?r is high, the Qf value is high and, the temperature coefficient ?f can be controlled while maintaining the temperature coefficient ?f at the resonant frequency small and the Qf value high. According to the invention, when, in an LnAlO3—CaTiO3-based dielectric porcelain composition, a molar ratio of LnAlO3 and CaTiO3 is optimized and Al is substituted by a slight amount of Ga, a structure that has an LnAlO3—CaTiO3 solid solution as a main phase and a solid solution of Al—Ga-based oxide as a secondary phase and does not substantially contain ?-Al2O3 in the structure can be obtained, and the temperature coefficient ?f can be controlled while maintaining the temperature coefficient ?f at the resonant frequency small and the Qf value high.

Abstract: The invention intends to provide a dielectric porcelain composition for use in electronic devices, in which the relative dielectric constant ?r is high, the Qf value is high and, the temperature coefficient ?f can be controlled while maintaining the temperature coefficient ?f at the resonant frequency small and the Qf value high. According to the invention, when, in an LnAlO3—CaTiO3-based dielectric porcelain composition, a molar ratio of LnAlO3 and CaTiO2 is optimized and Al is substituted by a slight amount of Ga, a structure that has an LnAlO3—CaTiO3 solid solution as a main phase and a solid solution of Al—Ga-based oxide as a secondary phase and does not substantially contain ?-Al2O3 in the structure can be obtained, and the temperature coefficient ?f can be controlled while maintaining the temperature coefficient ?f at the resonant frequency small and the Qf value high.

Abstract: The invention intends to provide a dielectric porcelain composition for use in electronic devices, which has the dielectric characteristics such that the Qf value is high, the temperature coefficient ?f of a resonant frequency is small and a value thereof can be controlled in a wide range in positive and negative directions in the vicinity where the relative dielectric constant ?r is 39. According to the invention, when, in La—Pr—Al—Ga—Sr—Ti-based oxide dielectric porcelain, contents of the respective elements are limited to be within particular ranges and Sr is partially substituted by Ca, a structure having a (1-x)(La1-yLny)(Al1-zGaz)O3-x(Sr1-mCam)TiO3 solid solution as a main phase, in which a solid solution of Al—Ga—Sr-based oxide and/or a solid solution of Al—Ga-based oxide and a Sr oxide is/are precipitated in a grain boundary thereof, can be obtained, whereby the above-mentioned object can be achieved.

Abstract: The invention intends to provide a dielectric porcelain composition for use in electronic devices, which has the dielectric characteristics such that the Qf value is high, the temperature coefficient ?f of a resonant frequency is small and a value thereof can be controlled in a wide range in positive and negative directions in the vicinity where the relative dielectric constant ?r is 39. According to the invention, when, in La—Pr—Al—Ga—Sr—Ti-based oxide dielectric porcelain, contents of the respective elements are limited to be within particular ranges and Sr is partially substituted by Ca, a structure having a (1-x)(La1-yLny)(Al1-zGaz)O3-x(Sr1-mCam)TiO3 solid solution as a main phase, in which a solid solution of Al—Ga—Sr-based oxide and/or a solid solution of Al—Ga-based oxide and a Sr oxide is/are precipitated in a grain boundary thereof, can be obtained, whereby the above-mentioned object can be achieved.

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.