Abstract: A method for producing a particle, containing a step of heating a mixture containing TiH2 and TiO2 at 700 to 950° C., wherein a molar ratio of the TiH2 to the TiO2 contained in the mixture is 5.0 to 6.8.

Abstract: A phosphor in which at least some of an element M in a phosphor host crystal represented by M?(L,A)?X? is substituted with Eu as an activation material. M represents one or more (including at least Sr) of Mg, Ca, Sr, Ba, and Zn, L represents one or more of Li, Na, and K, A represents one or more of Al, Ga, B, In, Sc, Y, La, and Si, X represents one or more (except that X represents only N) of O, N, F, and Cl, ?, ?, ?, and ? satisfy 8.70??+?+?+??9.30, 0.00<??1.30, 3.70???4.30, 3.70???4.30, and 0.00<??1.30. In a fluorescence spectrum obtained by irradiation with light having a wavelength of 260 nm, when a fluorescence intensity at a wavelength of 569 nm is represented by I0 and a fluorescence intensity at a wavelength of 617 nm is represented by I1, I1/I0 is 0.01 or more and 0.4 or less.

Abstract: Provided are an ?-SiAlON activated by Eu, which can realize a higher luminance in a light-emitting device such as a white LED, and also a light-emitting device. The ?-SiAlON is represented by the general formula: (M)x(Eu)y(Si)12-(m+n)(Al)m+n(O)n(N)16-n (wherein M denotes one or more elements including at least Ca, selected from the group consisting of Li, Mg, Ca, Y and lanthanide elements (except for La and Ce)), and is constituted by an ?-SiAlON having Eu in the form of a solid solution. The 50% mean area diameter of primary particles of the ?-SiAlON is 5 ?m or more, and the ratio of the 50% mean area diameter of primary particles to the 50% mean area diameter of secondary particles of the ?-SiAlON is preferably 0.56 or more.

Abstract: ?-sialon phosphor that is ?-sialon represented by a general expression: (M)x(Eu)y(Si, Al)12(O, N)16 (where M is one or more types of elements selected from a group consisting of Li, Mg, Ca, and Y as well as lanthanide element (except for La and Ce) and including at least Ca), the ?-sialon phosphor being structured so that an oxygen content is 1.2 mass % or less and primary particles constituting the ?-sialon have a columnar shape. When the ?-sialon phosphor receives ultraviolet rays or visible light having a wavelength from 250 to 500 nm as an excitation source, the ?-sialon phosphor shows a fluorescent characteristic having a peak in a wavelength region from 595 to 630 nm.

Abstract: Provided are an ?-SiAlON activated by Eu, which can realize a higher luminance in a light-emitting device such as a white LED, and also a light-emitting device. The ?-SiAlON is represented by the general formula: (M)x(Eu)y(Si)12?(m+n)(Al)m+n(O)n(N)16?n (wherein M denotes one or more elements including at least Ca, selected from the group consisting of Li, Mg, Ca, Y and lanthanide elements (except for La and Ce)), and is constituted by an ?-SiAlON having Eu in the form of a solid solution. The 50% mean area diameter of primary particles of the ?-SiAlON is 5 ?m or more, and the ratio of the 50% mean area diameter of primary particles to the 50% mean area diameter of secondary particles of the ?-SiAlON is preferably 0.56 or more.

Abstract: A fluorescent material comprising: a ?-Sialon expressed by the general formula Si6-ZAlZOZN8-Z as a host material; and Eu dissolved in solid solution as a luminescence center, is a powder which, when measured by the laser diffraction scattering method, gives particle diameter distribution in which cumulative 10% diameter (D10) falls within the 7 ?m to 20 ?m range and 90% diameter (D90) within the 50 ?m to 90 ?m range, and can be used as a fluorescent material low in luminescence intensity degradation ideal for illuminators. This fluorescent material can be produced by subjecting a raw powder, which is obtained by mixing a silicon nitride powder, aluminum nitride powder, and aluminum-containing or Eu-containing compound as required, to heating at 1850° C. to 2050° C. for 9 hours or longer in a nitrogen or nonoxidizing atmosphere.

Abstract: ?-sialon phosphor that is ?-sialon represented by a general expression: (M)x(Eu)y(Si, Al)12(O, N)16 (where M is one or more types of elements selected from a group consisting of Li, Mg, Ca, and Y as well as lanthanide element (except for La and Ce) and including at least Ca), the ?-sialon phosphor being structured so that an oxygen content is 1.2 mass % or less and primary particles constituting the ?-sialon have a columnar shape. When the ?-sialon phosphor receives ultraviolet rays or visible light having a wavelength from 250 to 500 nm as an excitation source, the ?-sialon phosphor shows a fluorescent characteristic having a peak in a wavelength region from 595 to 630 nm.

Abstract: A fluorescent material comprising: a ?-Sialon expressed by the general formula Si6-ZAlZOZN8-Z as a host material; and Eu dissolved in solid solution as a luminescence center, is a powder which, when measured by the laser diffraction scattering method, gives particle diameter distribution in which cumulative 10% diameter (D10) falls within the 7 ?m to 20 ?m range and 90% diameter (D90) within the 50 ?m to 90 ?m range, and can be used as a fluorescent material low in luminescence intensity degradation ideal for illuminators. This fluorescent material can be produced by subjecting a raw powder, which is obtained by mixing a silicon nitride powder, aluminum nitride powder, and aluminum-containing or Eu-containing compound as required, to heating at 1850° C. to 2050° C. for 9 hours or longer in a nitrogen or nonoxidizing atmosphere.