Abstract: The invention provides a green fluorescent substance being higher in luminance of green than a conventional rare-earth activated sialon fluorescent substance and more excellent in durability than a conventional oxide fluorescent substance. The inventors have succeeded in acquiring a fluorescent substance which is obtained by solid-dissolving Eu into a nitride or oxy-nitride crystal having a ?-type Si3N4 crystal structure and emits a fluorescent light having a peak within a range of 500 nm to 600 nm in wavelength by being irradiated with an excitation source.

Abstract: The invention has for its object the provision of an oxynitride fluorescent material has higher emission luminance than conventional rare earth element-activated sialon fluorescent materials. To this end, an oxynitride fluorescent material is designed in such a way as to contain as the primary constituent a JEM phase represented by a general formula MA1(Si6?zAlz)N10?zOz wherein M is one or two or more elements selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. For instance, this fluorescent material has a fluorescent spectrum maximum emission wavelength of 420 nm to 500 nm inclusive and an excitation spectrum maximum emission excitation wavelength of 250 nm to 400 nm inclusive.

Abstract: An object of the present invention is to provide an inorganic phosphor having fluorescence properties emitting an orange or red light which has a longer wavelength as compared with the cases of conventional sialon phosphors activated with a rare earth. The invention relates to a design of white light-emitting diode rich in a red component and having good color-rendering properties by employing a solid solution crystal phase phosphor which uses as a host crystal an inorganic compound having the same crystal structure as that of a CaSiAlN3 crystal phase and to which M Element (wherein M Element is one or two or more elements selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb) is added as an emission center.

Abstract: A fluorescence emitting device is provided using a phosphor emitting a light by bombardment of an electron beam and having excellent luminance lifetime. The electron beam excited phosphor comprises a solid solution prepared by an AIN crystal or AIN solid solution crystal formed with at least Eu, Si and oxygen represented by the composition formula Eua AIb Sic Nd Oe[Wherein a+b+c+d+e=1, and a, b, c, d and e satisfy the following conditions: 0.00001?a?0.1 0.4?b?0.55 0.001?c?0.1 0.4?d?0.55 0.001?e?0.

Abstract: Powdered fluorescent material excited by visible light that emits visible light has particles with particle sizes of 20 ?m or less in the content of below 2% by mass. The method for manufacturing a powdered fluorescent material comprises the steps of: sintering raw material powder of the fluorescent material; and chemically processing the sintered powder after said sintering with acid solution.

Abstract: A light-emitting device and illumination apparatus using the same are provided. The light-emitting device includes a semiconductor light-emitting element that emits blue-violet or blue light and a fluorescent material that absorbs the light emitted by the semiconductor light-emitting element and emits fluorescence of wavelengths different from the light, wherein the fluorescent material includes a mixture of a first fluorescent material, a second fluorescent material that has a longer emission wavelength than that of the first fluorescent material, and a third fluorescent material that has a longer emission wavelength than the second fluorescent material, and the first fluorescent material is a europium-activated ?-SiAlON fluorescent material, the second fluorescent material is a europium-activated ?-SiAlON fluorescent material, and the third fluorescent material is a nitride crystalline red fluorescent material of a general formula of (Ca,Eu)AlSiN3.

Abstract: A phosphor which is excited by a blue light and emits a yellow light has been conventionally known as a SiAlON phosphor wherein a rare earth element such as Eu ion is activated. The present invention provides an oxynitride phosphor having emission characteristics of more various wavelengths and a light-emitting device using such an oxynitride phosphor. The oxynitride phosphor mainly contains a crystalline phase of the general formula: La3Si8N11O4 or a crystalline phase of the general formula: La3Si8?xAlxN11?xO4+x (0<x?4), and an optically active element (M) composed of one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu is added thereto as a luminescent center component.

Abstract: The invention provides an oxynitride phosphor represented by a composition formula M1-aCeaSibAlcOdNe, wherein M denotes La or a compound of which main component is La and sub-component is at least one kind of element selected from the group consisting of Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb and Lu; the a that represents a composition ratio of Ce is a real number satisfying 0.1?a?1; the b that represents a composition ratio of Si is a real number satisfying b=(6?z)×f; the c that represents a composition ratio of Al is a real number satisfying c=(1+z)×g; the d that represents a composition ratio of O is a real number satisfying d=z×h; the e that represents a composition ratio of N is a real number satisfying e=(10?z)×i; the z is a real number satisfying 0.1?z?3; the f is a real number satisfying 0.7?f?1.3; the g is a real number satisfying 0.7?g?3; the h is a real number satisfying 0.7?h?3; the i is a real number satisfying 0.7?i?1.

Abstract: An incandescent lamp color light emitting diode lamp comprises a semiconductor blue light emitting diode chip having a center emission wavelength in a range of from 400 nm to 480 nm and a phosphor that absorbs light emitted from the diode chip to emit light having a different wavelength than the light emitted from the diode chip. The phosphor is represented by a general formula of Mp(Si, Al)12(O, N)16:Eu2+q. The main phase is an ?-SiAlON phosphor having an ? SiAlON structure, wherein M is at least one element of Ca, Y, Mg, Li, Sc, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sr and p is from 0.75 to 1.0; and q is between 0.02 and 0.09. The diode lamp emits light having an emission color produced by a mixture of the light emitted from the semiconductor blue light emitting and the light emitted from the ?-SiAlON. The chromaticity range thereof falls within the range defined by chromaticity coordinates (x, y) of (0.4775, 0.4283), (0.4594, 0.3971), (0.4348, 0.4185), and (0.4214, 0.

Abstract: A preferred embodiment according to the present invention provides in one preferred mode an oxynitride phosphor especially suitable for a light emitting device such as but not limited to a white light emitting diode lamp and also such a light emitting device. The oxynitride phosphor in the embodiment is represented by a general formula Cax(Si,Al)12(O,N)16:Eu2+y, wherein a Ca composition of x is in a range of from 0.75 to 1.0 and a Eu composition of y is in a range of from 0.04 to 0.25, and wherein a main phase thereof has substantially an alpha SiAlON crystal structure.

Abstract: A light emitting device comprises at least two lead wires, a light emitting element that is disposed on an end portion of at least one of said lead wires and connected electrically with the end portion and the other lead wire, and a phosphor that absorbs at least part of the light emitted from said light emitting element and emanates light having different wavelengths from the wavelength of the light emitted from said light emitting element, wherein the excitation spectrum of said phosphor has a flat region in a wavelength range including a primary wavelength of the light from said light emitting element.

Abstract: A silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase, wherein the grain boundary phase consists essentially of a single phase of a Lu4Si2O7N2 crystal phase, and the composition of the silicon nitride sintered product is a composition in or around a triangle ABC having point A: Si3N4, point B: 28 mol % SiO2-72 mol % Lu2O3 and point C: 16 mol % SiO2-84 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system. Also disclosed is a silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase of an oxynitride, wherein the composition of the sintered product is a composition in a triangle having point A: Si3N4, point B: 40 mol % SiO2-60 mol % Lu2O3 and point C: 60 mol % SiO2-40 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system.

Abstract: A silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase, wherein the grain boundary phase consists essentially of a single phase of a Lu4Si2O7N2 crystal phase, and the composition of the silicon nitride sintered product is a composition in or around a triangle ABC having point A: Si3N4, point B: 28 mol % SiO2-72 mol % Lu2O3 and point C: 16 mol % SiO2-84 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system. Also disclosed is a silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase of an oxynitride, wherein the composition of the sintered product is a composition in a triangle having point A: Si3N4, point B: 40 mol % SiO2-60 mol % Lu2O3 and point C: 60 mol % SiO2-40 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system.

Abstract: A silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase, wherein the grain boundary phase consists essentially of a single phase of a Lu4Si2O7N2 crystal phase, and the composition of the silicon nitride sintered product is a composition in or around a triangle ABC having point A: Si3N4, point B: 28 mol % SiO2-72 mol % Lu2O3 and point C: 16 mol % SiO2-84 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system. Also disclosed is a silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase of an oxynitride, wherein the composition of the sintered product is a composition in a triangle having point A: Si3N4, point B: 40 mol % SiO2-60 mol % Lu2O3 and point C: 60 mol % SiO2-40 mol % Lu2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—Lu2O3 system.

Abstract: A silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase, wherein the grain boundary phase consists essentially of a single phase of a LU4Si2O7N2 crystal phase, and the composition of the silicon nitride sintered product is a composition in or around a triangle ABC having point A: Si3N4, point B: 28 mol % SiO2-72 mol % LU2O3 and point C: 16 mol % SiO2-84 mol % LU2O3, as three apexes, in a ternary system phase diagram of a Si3N4—SiO2—LU2O3 system. Also disclosed is a silicon nitride sintered product comprising silicon nitride grains and a grain boundary phase of an oxynitride, wherein the composition of the sintered product is a composition in a triangle having point A: Si3N4, point B: 40 mol % SiO2-60 mol % LU2O3 and point C: 60 mol % SiO2-40 mol % LU2O3, as three apexes, in a ternary system phase diagram of a Si3N4-SiO2-LU2O3 system.

Abstract: A sintered silicon nitride excellent in high temperature performance is produced by the following method: First, silicon nitride powder and oxide of at least one element selected from elements in the group IIIb of a periodic table are mixed with each other to obtain a mixture. The silicon nitride powder contains silicon oxide in an amount ranging from 0.1% by weight of the silicon nitride powder to a value not more than a content of the silicon oxide. Second, the mixture is compacted to form a compact. Finally, the compact is fired in atmosphere of nitrogen at a pressure ranging from 5 to 200 atmosphere (atm) and a temperature ranging from 1800.degree. to 2000.degree. C. to obtain a sintered silicon nitrite having a bulk density not less than 95% of a theoretical density of the sintered silicon nitride.

Abstract: The invention relates to a sintered composite of silicon carbide and silicon nitride. The sintered composite includes a polycrystalline matrix and polycrystalline aggregates dispersed in the matrix. The matrix includes silicon carbide grains, first silicon-nitride grains and a first sintering aid thereof. Each of the aggregates includes second silicon-nitride grains and a second sintering aid thereof. The aggregates have an average diameter within a range from 10 .mu.m to 50 .mu.m. This average diameter is defined as a diameter of a circle having an area which is the same as the average area of the aggregates on a two-dimensional section of the sintered composite. The sintered composite is light in weight and superior in strength and fracture toughness at high temperature as well as at room temperature.

Abstract: A high strength and toughness .beta.-silicon nitride sintered body suitable for the material of a variety of structural parts. The sintered body contains .beta.-silicon nitride (Si.sub.3 N.sub.4) in an amount not less than 95% by weight of total silicon nitride; oxygen in a total amount not more than 3% by weight of the sintered body; and columnar grains each of which has a diameter not less than 5 .mu.m and an aspect ratio not less than 5, the columnar grains being in an amount not less than 0.5% by volume of total of raw materials in the sintered body; the sintered body having a bulk density not less than 96% of a theoretical density. Such a sintered body is produced by a method comprising the following steps in the sequence set forth: preparing powder of a starting material including .beta.-silicon nitride in an amount not less than 80% by weight of the starting material; adding oxide of at least one element selected from the group IIIa of the periodic table of elements in an amount ranging from 0.

Abstract: A high strength and toughness .beta.-silicon nitride sintered body suitable for the material of a variety of structural parts. The sintered body contains .beta.-silicon nitride (Si.sub.3 N.sub.4) in an amount not less than 95% by weight of total silicon nitride; oxygen in a total amount not more than 3% by weight of the sintered body; and columnar grains each of which has a diameter not less than 5 .mu.m and an aspect ratio not less than 5, the columnar grains being in an amount not less than 0.5% by volume of total of raw materials in the sintered body; the sintered body having a bulk density not less than 96% of a theoretical density. Such a sintered body is produced by a method comprising the following steps in the sequence set forth: preparing powder of a starting material including .beta.-silicon nitride in an amount not less than 80% by weight of the starting material; adding oxide of at least one element selected from the group IIIa of the periodic table of elements in an amount ranging from 0.

Abstract: A method for producing a sintered silicon carbide and sialon composite includes the following steps in the sequence: sintering a mixture including .alpha.-sialon powder, .alpha.-silicon nitride powder and .beta.-silicon carbide powder by hot pressing at a first predetermined temperature; and resintering the sintered mixture at a pressure of nitrogen gas ranging from 100 to 2000 atmosphere and at a second predetermined temperature 100.degree. to 200.degree. C. higher than the first predetermined temperature.