Abstract: A ?-SiAlON fluorescent material includes fluorescent material particles having a composition represented by the following formula (I), and a coating layer formed on the surface of the fluorescent material particles and having a refractive index smaller than that of the fluorescent material particles, wherein when the ?-SiAlON fluorescent material is measured by inductively coupled plasma-atomic emission spectroscopy, an amount of the coating layer is 0.4% by mass or more relative to a total amount of the fluorescent material particles and the coating layer being 100% by mass: Si6-zAlzOzN8-z:Euy??(I), wherein y and z satisfy 0<y?1.0 and 0<z?4.2.

Abstract: Provided a method of producing a ?-sialon fluorescent material having excellent emission intensity. The method includes providing a first composition containing aluminum, an oxygen atom, and a europium-containing silicon nitride, heat treating the first composition, contacting the heat-treated composition and a basic substance to obtain a second composition, and contacting the second composition resulting from contacting the heat-treated composition with the basic substance and an acidic liquid medium containing an acidic substance.

Abstract: Provided is a method of producing a ?-sialon fluorescent material having a high light emission intensity and an excellent light emission luminance. The method includes preparing a calcined product having a composition of ?-sialon containing an activating element; grinding the calcined product to obtain a ground product; and heat-treating the ground product to obtain a heat-treated product. A specific surface area of the ground product is 0.2 m2/g or more.

Abstract: Provided a method of producing a ?-sialon fluorescent material having excellent emission intensity. The method includes providing a first composition containing aluminum, an oxygen atom, and a europium-containing silicon nitride, heat treating the first composition, contacting the heat-treated composition and a basic substance to obtain a second composition, and contacting the second composition resulting from contacting the heat-treated composition with the basic substance and an acidic liquid medium containing an acidic substance.

Abstract: A wavelength converting member comprising a first wavelength converting layer containing: a first fluorescent material having a light emission peak wavelength in a range of 620 nm or more and 660 nm or less; a second fluorescent material having a light emission peak wavelength in a range of 510 nm or more and 560 nm or less; and a resin, wherein the average particle diameter, as measured according to a Fisher Sub-Sieve Sizer method, of the first fluorescent material is in a range of 2 ?m or more and 30 ?m or less, wherein the second fluorescent material comprises a ?-SiAlON fluorescent material, the circularity of the ?-SiAlON fluorescent material is 0.7 or more, and the volume average particle diameter, as measured according to a laser diffraction scattering particle size distribution measuring method, of the ?-SiAlON fluorescent material is in a range of 2 ?m or more and 30 ?m or less, and wherein the thickness of the first wavelength converting layer is in a range of 50 ?m or more and 200 ?m or less.

Abstract: A method for producing ?-sialon fluorescent material having excellent emission intensity is provided. The method for producing ?-sialon fluorescent material includes providing a composition comprising silicon nitride that contains aluminium, an oxygen atom, and europium, heat treating the composition, contacting the heat-treated composition with a basic substance, and washing the composition, which has been contacted with the basic substance, with an acidic liquid medium.

Abstract: A wavelength converting member comprising a first wavelength converting layer containing: a first fluorescent material having a light emission peak wavelength in a range of 620 nm or more and 660 nm or less; a second fluorescent material having a light emission peak wavelength in a range of 510 nm or more and 560 nm or less; and a resin, wherein the average particle diameter, as measured according to a Fisher Sub-Sieve Sizer method, of the first fluorescent material is in a range of 2 ?m or more and 30 ?m or less, wherein the second fluorescent material comprises a ?-SiAlON fluorescent material, the circularity of the ?-SiAlON fluorescent material is 0.7 or more, and the volume average particle diameter, as measured according to a laser diffraction scattering particle size distribution measuring method, of the ?-SiAlON fluorescent material is in a range of 2 ?m or more and 30 ?m or less, and wherein the thickness of the first wavelength converting layer is in a range of 50 ?m or more and 200 ?m or less.

Abstract: Provided is a method of producing a ?-sialon fluorescent material having a high light emission intensity and an excellent light emission luminance. The method includes preparing a calcined product having a composition of ?-sialon containing an activating element; grinding the calcined product to obtain a ground product; and heat-treating the ground product to obtain a heat-treated product. A specific surface area of the ground product is 0.2 m2/g or more.

Abstract: A method for producing a ?-sialon fluorescent material can be provided. The method includes preparing a composition containing silicon nitride that contains aluminium, an oxygen atom, and europium, heat-treating the composition in a rare gas atmosphere or in a vacuum, and contacting the heat-treated composition with a gas containing elemental fluorine.

Abstract: A method for producing a ?-sialon fluorescent material is provided. The method includes heat-treating a mixture containing an aluminium compound, a first europium compound, and silicon nitride to obtain a first heat-treated product; and heat-treating the first heat-treated product with a second europium compound in a rare gas atmosphere to obtain a second heat-treated product.

Abstract: A method for producing a ?-sialon fluorescent material superior in light emitting luminance is provided. The method includes heat-treating a first mixture containing an aluminum compound, a europium compound, and a first silicon oxynitride compound to obtain a first heat-treated product, and heat-treating a second mixture containing the first heat-treated product, an aluminum compound, a europium compound, and a second silicon oxynitride compound, which has a larger oxygen content than the first silicon oxynitride compound, to obtain a second heat-treated product.

Abstract: A phosphor, which is represented by the general formula containing M, Ce, Pr, Si, and N, is provided. M is at least one element selected from the group consisting of La, Y, Tb and Lu. A molar ratio of M is greater than 2.0 and smaller than 3.5. A molar ratio of Ce is greater than 0 and smaller than 1.0. A molar ratio of Pr is greater than 0 and smaller than 0.05. A molar ratio of N is greater than 10 and smaller than 12, under the condition that a molar ratio of Si is set to 6. The phosphor further contains 10 to 10,000 ppm of fluorine.

Abstract: A fluorescent material is provided that has improved luminance and can generate fluorescence by excitation light in wider wavelength range. A fluorescent material represented by a general formula LaxCeySi6N8+x+y, wherein 2.0?x?3.5, 0<y?1.0, wherein the fluorescent material comprises 10 to 10000 ppm of Ba and/or Sr, and wherein a first wavelength and a second wavelength at which excitation intensities are 70% of the maximum of the excitation intensities are present in a wavelength range of 400 to 510 nm, the second wavelength being longer than the first wavelength, and a difference between the first wavelength and the second wavelength being 70 nm or more.

Abstract: A phosphor is provided which is represented by the general formula MxCeyPrzSi6N8+w. M is at least one element selected from the group consisting of La, Y, Tb and Lu. And x, y, z and w satisfy 2.0<x<3.5, 0<y<1.0, 0<z<0.05, and 2.0<w<4.0, respectively.

Abstract: A phosphor is provided which is represented by the general formula MxCeySi6?zBzN8+w. M is at least one element selected from the group consisting of La, Y, Tb and Lu. And w, x, y, and z satisfy 2.0<w<4.0, 2.0<x<3.5, 0<y<1.0, and 0<z<2.0, respectively. The phosphor can be efficiently excited by light in a range from near-ultraviolet to blue light, and emit light having components that widely extend mainly from green range to yellow range. A light-emitting apparatus includes the phosphor together with a light-emitting device that emits light in a range from near-ultraviolet to blue light, and can have improved light emission efficiency, good color rendering property, and good color reproduction range. In the case where a light-emitting apparatus includes an additional phosphor, it is possible to further improve its light emission spectrum.