Abstract: A component body is obtained by alternately laminating and sintering a plurality of semiconductor ceramic layers formed of a SrTiO3-based grain boundary insulated semiconductor ceramic and a plurality of internal electrode layers. The average grain diameter of crystal grains is 1.0 ?m or less and a coefficient of variation representing variations in a grain diameter of the crystal grains is 30% or less. To prepare the semiconductor ceramic an Sr compound, a Ti compound and a donor compound are weighed in predetermined amounts and mixed/pulverized. A calcined powder is prepared and a dispersant is added with an acceptor compound to the calcined powder. The resulting mixture is wet-mixed and a heat-treated powder is prepared. The heat-treated powder is formed into slurry and subjected to a filter treatment. The filtered slurry is used to prepare a semiconductor ceramic.

Abstract: A component body is obtained by alternately laminating and sintering a plurality of semiconductor ceramic layers formed of a SrTiO3-based grain boundary insulated semiconductor ceramic and a plurality of internal electrode layers. The average grain diameter of crystal grains is 1.0 ?m or less and a coefficient of variation representing variations in a grain diameter of the crystal grains is 30% or less. To prepare the semiconductor ceramic an Sr compound, a Ti compound and a donor compound are weighed in predetermined amounts and mixed/pulverized. A calcined powder is prepared and a dispersant is added with an acceptor compound to the calcined powder. The resulting mixture is wet-mixed and a heat-treated powder is prepared. The heat-treated powder is formed into slurry and subjected to a filter treatment. The filtered slurry is used to prepare a semiconductor ceramic.

Abstract: A ceramic powder for use in a grain boundary insulated semiconductor ceramic that has an excellent ESD withstanding voltage, a semiconductor ceramic capacitor using the ceramic powder, and a manufacturing method therefor. The ceramic powder for use in a SrTiO3 based grain boundary insulated semiconductor ceramic has a specific surface area of 4.0 m2/g or more and 8.0 m2/g or less, and a cumulative 90% grain size D90 of 1.2 ?m or less.

Abstract: A semiconductor ceramic contains a donor element solid-solved in crystal grains of a SrTiO3-based compound, and an acceptor element in a grain boundary layer. The number of tetravalent acceptor elements is 1×1017/g or more, as determined from an electron spin resonance absorption spectrum. A mixture of a calcined powder and an acceptor compound is pulverized to a specific surface area of 5.0 to 7.5 m2/g before mixing with a binder. Semiconductor ceramic layers having a varistor function are formed by using the semiconductor ceramic forming a highly reliable capacitor which can suppress characteristics variations to stably obtain good electrical characteristics.

Abstract: A semiconductor ceramic having a compounding molar ratio m between a Sr site and a Ti site that satisfies 1.000 ?m?1.020, has a donor element present as a solid solution in crystal grains, has an acceptor element present in a grain boundary layer in the range of 0.5 mol or less with respect to 100 mol of the Ti element, contains a Zr element in the range of 0.15 mol or more and 3.0 mol or less with respect to 100 mol of the Ti element, and has the crystal grains of 1.5 ?m or less in average grain size.

Abstract: A semiconductor ceramic having a compounding molar ratio m between a Sr site and a Ti site that satisfies 1.000?m?1.020, has a donor element present as a solid solution in crystal grains, has an acceptor element present in a grain boundary layer in the range of 0.5 mol or less with respect to 100 mol of the Ti element, contains a Zr element in the range of 0.15 mol or more and 3.0 mol or less with respect to 100 mol of the Ti element, and has the crystal grains of 1.5 ?m or less in average grain size.

Abstract: A ceramic powder for use in a grain boundary insulated semiconductor ceramic that has an excellent ESD withstanding voltage, a semiconductor ceramic capacitor using the ceramic powder, and a manufacturing method therefor. The ceramic powder for use in a SrTiO3 based grain boundary insulated semiconductor ceramic has a specific surface area of 4.0 m2/g or more and 8.0 m2/g or less, and a cumulative 90% grain size D90 of 1.2 ?m or less.

Abstract: A laminate type semiconductor ceramic capacitor with a varistor function is achieved which allows for an improvement in product yield while ensuring such insulation performance that can withstand practical use, and is suitable for mass production with a favorable ESD withstanding voltage. The semiconductor ceramic forming the semiconductor ceramic layers has a compounding molar ratio m between the Sr site and the Ti site of 0.990?m<1.000, has a donor element such as La present as a solid solution in crystal grains, has an acceptor element such as Mn present in a grain boundary layer in the range of 0.5 mol or less (preferably 0.3 mol to 0.5 mol) with respect to 100 mol of the Ti element, and has the crystal grains with an average grain size of 1.5 ?m or less.

Abstract: A semiconductor ceramic contains a donor element solid-solved in crystal grains of a SrTiO3-based compound, and an acceptor element in a grain boundary layer. The number of tetravalent acceptor elements is 1×1017/g or more, as determined from an electron spin resonance absorption spectrum. A mixture of a calcined powder and an acceptor compound is pulverized to a specific surface area of 5.0 to 7.5 m2/g before mixing with a binder. Semiconductor ceramic layers having a varistor function are formed by using the semiconductor ceramic forming a highly reliable capacitor which can suppress characteristics variations to stably obtain good electrical characteristics.

Abstract: A laminate type semiconductor ceramic capacitor with a varistor function is achieved which allows for an improvement in product yield while ensuring such insulation performance that can withstand practical use, and is suitable for mass production with a favorable ESD withstanding voltage. The semiconductor ceramic forming the semiconductor ceramic layers has a compounding molar ratio m between the Sr site and the Ti site of 0.990?m<1.000, has a donor element such as La present as a solid solution in crystal grains, has an acceptor element such as Mn present in a grain boundary layer in the range of 0.5 mol or less (preferably 0.3 mol to 0.5 mol) with respect to 100 mol of the Ti element, and has the crystal grains with an average grain size of 1.5 ?m or less.

Abstract: A SrTiO3-based grain boundary insulation type semiconductor ceramic contains a donor element in solid solution in crystal grains, an acceptor element at least in crystal grain boundaries, an integral width of (222) face of the crystal face of 0.500° or less, and an average powder grain size of crystal grains of 1.0 ?m or less. A semiconductor ceramic is obtained by firing this ceramic, and a monolithic semiconductor ceramic capacitor is obtained by using the semiconductor ceramic. The SrTiO3-based grain boundary insulation type semiconductor ceramic powder has a large apparent relative dielectric constant ?rAPP of 5,000 or more even when the average ceramic grain size of crystal grains is 1.0 ?m or less and which has an excellent insulating property. The monolithic semiconductor ceramic capacitor is capable of having a large capacity through reduction in thickness and multilayering.

Abstract: A semiconductor ceramic has a mixing molar ratio m between the Sr site and the Ti site satisfying the relationship 1.000?m<1.020, a donor element in an amount of 0.8 to 2.0 moles relative to 100 moles of the Ti element dissolved in the Sr site to form a solid solution, the donor element having a higher valency than the Sr element, a transition metal element, such as Mn, incorporated in an amount of 0.3 to 1.0 mole relative to 100 moles of the Ti element so as to be segregated in grain boundaries, and an average grain size of crystal grains is 1.0 ?m or less.

Abstract: A semiconductor ceramic comprising a donor element within the range of 0.8 to 2.0 mol relative to 100 mol of Ti element contained as a solid solution with crystal grains, a first acceptor element in an amount less than the amount of the donor element is contained as a solid solution with the crystal grains, a second acceptor element within the range of 0.3 to 1.0 mol relative to 100 mol of a Ti element is present in crystal grain boundaries, and the average grain size of the crystal grains is 1.0 ?m or less. A monolithic semiconductor ceramic capacitor is obtained by using this semiconductor ceramic. To form the semiconductor ceramic, in a first firing treatment to conduct reduction firing, a cooling treatment is conducted while the oxygen partial pressure at the time of starting the cooling is set at 1.0×104 times or more the oxygen partial pressure in the firing process.

Abstract: A SrTiO3-based grain boundary insulation type semiconductor ceramic contains a donor element in solid solution in crystal grains, an acceptor element at least in crystal grain boundaries, an integral width of (222) face of the crystal face of 0.500° or less, and an average powder grain size of crystal grains of 1.0 ?m or less. A semiconductor ceramic is obtained by firing this ceramic, and a monolithic semiconductor ceramic capacitor is obtained by using the semiconductor ceramic. The SrTiO3-based grain boundary insulation type semiconductor ceramic powder has a large apparent relative dielectric constant ?rAPP of 5,000 or more even when the average ceramic grain size of crystal grains is 1.0 ?m or less and which has an excellent insulating property. The monolithic semiconductor ceramic capacitor is capable of having a large capacity through reduction in thickness and multilayering.

Abstract: A monolithic semiconductor ceramic capacitor includes semiconductor ceramic layers made of a semiconductor ceramic having a Sr site and a Ti site. The semiconductor ceramic satisfies the inequality 1.000<m?1.020, wherein m represents the molar ratio of the Sr site to the Ti site. The semiconductor ceramic contains crystal grains and has grain boundary layers. The crystal grains contain a donor element such as La or Sm in the form of a solid solution. The grain boundary layers contain an acceptor element such as Mn, Co, Ni or Cr. The amount of the acceptor element therein is equal to or less than 0.5 mol (preferably 0.3 to 0.5 mol) per 100 mol of Ti. The crystal grains have an average size of 1.0 ?m or less (preferably 0.5 to 0.8 ?m). Therefore, the monolithic semiconductor ceramic capacitor has good electrical properties, good resistivity, good dielectric strength, and high reliability and is suitable for thin or compact apparatuses.

Abstract: A semiconductor ceramic has a mixing molar ratio m between the Sr site and the Ti site satisfying the relationship 1.000?m<1.020, a donor element in an amount of 0.8 to 2.0 moles relative to 100 moles of the Ti element dissolved in the Sr site to form a solid solution, the donor element having a higher valency than the Sr element, a transition metal element, such as Mn, incorporated in an amount of 0.3 to 1.0 mole relative to 100 moles of the Ti element so as to be segregated in grain boundaries, and an average grain size of crystal grains is 1.0 ?m or less.

Abstract: A semiconductor ceramic comprising a donor element within the range of 0.8 to 2.0 mol relative to 100 mol of Ti element contained as a solid solution with crystal grains, a first acceptor element in an amount less than the amount of the donor element is contained as a solid solution with the crystal grains, a second acceptor element within the range of 0.3 to 1.0 mol relative to 100 mol of a Ti element is present in crystal grain boundaries, and the average grain size of the crystal grains is 1.0 ?m or less. A monolithic semiconductor ceramic capacitor is obtained by using this semiconductor ceramic. To form the semiconductor ceramic, in a first firing treatment to conduct reduction firing, a cooling treatment is conducted while the oxygen partial pressure at the time of starting the cooling is set at 1.0×104 times or more the oxygen partial pressure in the firing process.

Abstract: A monolithic semiconductor ceramic capacitor includes semiconductor ceramic layers made of a semiconductor ceramic having a Sr site and a Ti site. The semiconductor ceramic satisfies the inequality 1.000<m?1.020, wherein m represents the molar ratio of the Sr site to the Ti site. The semiconductor ceramic contains crystal grains and has grain boundary layers. The crystal grains contain a donor element such as La or Sm in the form of a solid solution. The grain boundary layers contain an acceptor element such as Mn, Co, Ni or Cr. The amount of the acceptor element therein is equal to or less than 0.5 mol (preferably 0.3 to 0.5 mol) per 100 mol of Ti. The crystal grains have an average size of 1.0 ?m or less (preferably 0.5 to 0.8 ?m). Therefore, the monolithic semiconductor ceramic capacitor has good electrical properties, good resistivity, good dielectric strength, and high reliability and is suitable for thin or compact apparatuses.

Abstract: A BaTiO3-type semiconducting ceramic material which has undergone firing in a reducing atmosphere and re-oxidation, wherein the relative density of the ceramic material after sintering is about 85–90%. A process for producing the semiconducting ceramic material of the present invention and a thermistor containing the semiconducting ceramic material are also disclosed.

Abstract: A ceramic electronic component includes a component body having semiconductive ceramic layers and internal electrodes. The semiconductive ceramic layers and the internal electrodes are alternately laminated. The semiconductive ceramic layers have a relative density of about 90% or less and contain no sintering additives. The component body is provided with an external electrode on each side thereof. The ceramic electronic component has a low resistance and a high withstand voltage.