Abstract: A fluorophor includes: ?-type sialon crystal which is expressed by a general formula: (Lix1, Eux2)(Si12?(m+n)Alm+n)(OnN16?n), wherein x1 is an amount of solid solution of Li in a sialon unit cell, and x2 is an amount of solid solution of Eu in the sialon unit cell, wherein the parameters x1, x2, m, and n satisfy: 1.6?x1?2.4 (1), 0.001?x2?0.4 (2), 1.8?m?2.4 (3), 0.8?n?1.2 (4), wherein the ?-type sialon crystal emits fluorescence with a peak in a wavelength region of from 550 nm to 575 nm upon irradiation of an excitation source.

Abstract: A fluorophor includes: ?-type sialon crystal which is expressed by a general formula: (Lix1, Eux2) (Si12?(m+n)Alm+n)(OnN16?n), wherein x1 is an amount of solid solution of Li in a sialon unit cell, and x2 is an amount of solid solution of Eu in the sialon unit cell, wherein the parameters x1, x2, m, and n satisfy: 1.6?x1?2.4 (1), 0.001?x2?0.4 (2), 1.8?m?2.4 (3), 0.8?n?1.2 (4), wherein the ?-type sialon crystal emits fluorescence with a peak in a wavelength region of from 550 nm to 575 nm upon irradiation of an excitation source.

Abstract: A fluorophor which comprises as a main component, an ? type sialon crystal containing at least Li, A element (wherein A represents one or more elements selected from among Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Er, Tm and Yb), M element (wherein M represents one or more metal elements except Li and the A element), Si, Al, oxygen and nitrogen. The fluorophor has an a type sialon crystal structure which is represented by the general formulae: (Lix1, Ax2, Mx3)(Si12?(m+n)Alm+n)(OnN16?n) 1.2?x1?2.4 (1) 0.001?x2?0.4 (2) and 0?x3?1.0 (3), and has a luminescence peak at a wavelength in the range of 400 to 700 nm. The above phosphor is reduced in the lowering of brightness, and can be suitably used for a white LED and the like.

Abstract: According to the invention, a highly crystalline ?-sialon is synthesized to emit highly intense light and a white LED showing an excellent color rendering characteristic is provided by shifting emitted light to the short wavelength side (blue shift). Such an ?-sialon is designed so as to be expressed by general formula (Lix, Cay, Euz) (Si12?(m+n)Alm+n) (OnN16?n) wherein the numerical ranges of x, y, z, m and n are respectively 0<x<2.0, 0<y<2.0, 0<z?0.5 (provided that 0.3?x+y+z?2.0), 0<m?4.0 and 0<n?3.0.

Abstract: An ?-sialon is offered which is represented by general formula: (M1)X(M2)Y(Si, Al)12(O, N)16 (wherein M1 represents one or more elements selected from the group which consists of Li, Mg, Ca, Y and lanthanoid (except La and Ce) and M2 represents one or more elements selected from the group which consists of Ce, Pr, Eu, Tb, Yb and Er and wherein 0.3<X+Y<1.5 and 0<Y<0.7), the ?-sialon containing from 30 ppm to 1% of fluorine as an impurity. By making primary particles of the ?-sialon 1 to 10 ?m in average particle size, an ?-sialon phosphor can be obtained reproducibly, stably and in a large quantity. Especially, if containing 30 to 200 ppm of impurity fluorine, the ?-sialon phosphor can exhibit an excellent emission characteristic as a white fluorescent matter.

Abstract: A light emitting apparatus has a light emitting element with an emission wavelength in the range of 360 to 550 nm and a rare-earth element doped oxide nitride phosphor or cerium ion doped lanthanum silicon nitride phosphor. Part of light radiated from the light emitting element is wavelength-converted by the phosphor. The light emitting apparatus radiates white light generated by a mixture of the wavelength-converted light and the other part of light radiated from the light emitting element.

Abstract: A fluorophor comprising, as a main component, an ?-type sialon crystal which contains at least an A element (wherein A represents one or more elements selected from among Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Er, Tm and Yb), an M element (wherein M represents one or more elements selected from among Li, Na, Mg, Ca, Y, La, Gd and Lu), Si, Al, oxygen and nitrogen, and is represented by the general formula: (Mx, Ay)(Si12?(m+n)Alm+n)(OnN16?n) (1) m=?M×x+?A×y (2) 0.2?x?2.4 (3) 0.001?y?0.4 (4) and 0.5×m<n?4 (5). The fluorophor is reduced in the lowering of brightness, and is useful for a white color LED and the like.

Abstract: According to the invention, a highly crystalline ?-sialon is synthesized to emit highly intense light and a white LED showing an excellent color rendering characteristic is provided by shifting emitted light to the short wavelength side (blue shift). Such an ?-sialon is designed so as to be expressed by general formula (Lix, Cay, Euz) (Si12-(m+n)Alm+n) (OnN16-n) wherein the numerical ranges of x, y, z, m and n are respectively 0<x<2.0, 0<y<2.0, 0<z?0.5 (provided that 0.3?x+y+z?2.0), 0<m?4.0 and 0<n?3.0.

Abstract: A fluorophor which comprises as a main component, an ? type sialon crystal containing at least Li, A element (wherein A represents one or more elements selected from among Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Er, Tm and Yb), M element (wherein M represents one or more metal elements except Li and the A element), Si, Al, oxygen and nitrogen. The fluorophor has an a type sialon crystal structure which is represented by the general formulae: (Lix1, Ax2, Mx3)(Si12?(m+n)Alm+n)(OnN16?n) 1.2?x1?2.4 (1) 0.001?x2?0.4 (2) and 0?x3?1.0 (3), and has a luminescence peak at a wavelength in the range of 400 to 700 nm. The above phosphor is reduced in the lowering of brightness, and can be suitably used for a white LED and the like.

Abstract: A fluorophor comprising, as a main component, an ?-type sialon crystal which contains at least an A element (wherein A represents one or more elements selected from among Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Er, Tm and Yb), an M element (wherein M represents one or more elements selected from among Li, Na, Mg, Ca, Y, La, Gd and Lu), Si, Al, oxygen and nitrogen, and is represented by the general formulae: (Mx, Ay)(Si12?(m+n)Alm+n)(OnN16?n) (1) m=?M×x+?A×y (2) 0.2?x?2.4 (3) 0.001?y?0.4 (4) and 0.5×m<n?4 (5). The fluorophor is reduced in the lowering of brightness, and is useful for a white color LED and the like.

Abstract: An ?-sialon is offered which is represented by general formula: (M1)X (M2)Y (Si, Al)12 (O, N)16 (wherein M1 represents one or more elements selected from the group which consists of Li, Mg, Ca, Y and lanthanoid (except La and Ce) and M2 represents one or more elements selected from the group which consists of Ce, Pr, Eu, Tb, Yb and Er and wherein 0.3<X+Y<1.5 and 0<Y<0.7), the ?-sialon containing from 30 ppm to 1% of fluorine as an impurity. By making primary particles of the ?-sialon 1 to 10 ?m in average particle size, an ?-sialon phosphor can be obtained reproducibly, stably and in a large quantity. Especially, if containing 30 to 200 ppm of impurity fluorine, the ?-sialon phosphor can exhibit an excellent emission characteristic as a white fluorescent matter.

Abstract: An ?-sialon which is represented by general formula: (M1)x (M2)y (Si, Al)12 (O, N)16 (wherein M1 represents one or more elements selected from the group which consists of Li, Mg, Ca, Y and lanthanoid (except La and Ce) and M2 represents one or more elements selected from the group which consists of Ce, Pr, Eu, Tb, Yb and Er and wherein 0.3<X+Y<1.5 and 0<Y<0.7) is synthesized by loading a container with a mixed powdery material of silicon nitride, aluminum nitride, an M1 containing compound and an M2 containing compound and at need aluminum oxide so that its bulk density is not more than 1.5 g/cm3, heat-treating the mixed powdery material at 1,600 to 2,000° C. in a nitrogen atmosphere. The ?-sialon is pulverized to make an ?-sialon powder, which can be utilized as a phosphor material for a while LED which uses a blue or an ultraviolet LED as its light source.

Abstract: A light emitting apparatus has a light emitting element with an emission wavelength in the range of 360 to 550 nm and a rare-earth element doped oxide nitride phosphor or cerium ion doped lanthanum silicon nitride phosphor. Part of light radiated from the light emitting element is wavelength-converted by the phosphor. The light emitting apparatus radiates white light generated by a mixture of the wavelength-converted light and the other part of light radiated from the light emitting element.

Abstract: The present invention provides a lanthanum sulfide or cerium sulfide sintered compact usable as a thermoelectric conversion material having a high Seebeck coefficient. The sintered compact has a chemical composition of La2S3 or Ce2S3, and a crystal structure consisting of a mixture of beta and gamma phases having a Seebeck coefficient higher than that of the crystal structure otherwise being in gamma single-phase. The sintered compact is produced by preparing a beta-phase La2S3 or alpha-phase Ce2S3 powder of raw material having a high purity with a suppressed carbon impurity concentration and a given range of oxygen concentration, charging the raw material into a carbon die having an inner surface covered with an h-BN applied thereon, and hot-pressing the charged material under vacuum to form a mixture of beta and gamma phases having a high Seebeck coefficient.

Abstract: A light emitting apparatus has a light emitting element with an emission wavelength in the range of 360 to 550 nm and a rare-earth element doped oxide nitride phosphor or cerium ion doped lanthanum silicon nitride phosphor. Part of light radiated from the light emitting element is wavelength-converted by the phosphor. The light emitting apparatus radiates white light generated by a mixture of the wavelength-converted light and the other part of light radiated from the light emitting element.

Abstract: An oxynitride phosphor activated by a rare earth element, represented by the formula CaxSi12−(m+n)Al(m+n)OnN16−n: EuyDyz, wherein stabilizing metal (Ca) is substituted partially by Eu or Eu and Dy where 0.3<x<1.5, 0.01<y<0.7, 0≦z<0.1, 0.6<m<3.0 and 0<n<1.5.

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 sialon type phosphor in the form of a powder comprising at least 40 wt % of &agr;-sialon represented by the formula (Cax,My)(Si,Al)12(O,N)16 (where M is at least one metal selected from the group consisting of Eu, Tb, Yb and Er, 0.05<(x+y)<0.3, 0.02<x<0.27 and 0.03<y<0.3) and having a structure such that Ca sites of Ca-&agr;-sialon are partially substituted by other metal M, at most 40 wt % of &bgr;-sialon, and at most 30 wt % of unreacted silicon nitride.

Abstract: An oxynitride phosphor activated by a rare earth element, represented by the formula MexSi12−(m+n)Al(m+n)OnN16−n:Re1yRe2x, wherein a part or all of metal Me (where Me is at least one metal selected from the group consisting of Ca, Mg, Y and lanthanide metals excluding La and Ce) in &agr;-sialon solid solution, is substituted by lanthanide metal Re1 (where Re1 is at least one metal selected from the group consisting of Ce, Pr, Eu, Tb, Yb and Er), or two lanthanide metals Re1 and a coactivator Re2 (where Re2 is Dy), to be an emission center.

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.