Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material is provided, which includes a carbide oxynitride-based compound having a composition represented by formula 1: (M1?wRw)uAl1?xSi1+vOzNtCy??formula 1 wherein M is at least one metal element excluding Si and Al, and R is a luminescent central element. w, u, x, v, z, t and y satisfy following relationships: 0.001<w<0.5; 0.66?u?1; 0.07?x?0.73; 0.06?v?0.84; 0.04?z?0.44; 2.7?t?3.1; and 0.019?y?0.13.

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2 ??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A fluorescent substance is provided, with includes a matrix composed of a compound having an AlN polytypoid structure represented by the following general formula (1), and a luminescence center element: (Al,M)a(N,X)b??(1) wherein, M is at least one metal excluding Al, X is at least one non-metal excluding N, and a and b are positive values.

Abstract: To provide a sintered silicon nitride with conductivity and densification, an oxide of titanium group elements, such as titanium oxide, hafnium oxide, zirconium oxide and the like, aluminum oxide and/or aluminum nitride is added as needed to silicon nitride-oxidant of rare-earth elements-aluminum oxide system or silicon nitride-oxide of rare-earth elements-magnesia system, and then specified quantity of carbon nonotube (CNT) is added to the above mixture. CNT generates silicon carbide after the reaction with contiguous or proximal silicon nitride and the like depending on the sintering duration at high temperature. Since silicon carbide is generated along with nanotubes, the silicon carbide functions as conductor with excellent heat resistance, corrosion resistance and the like.

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material is provided, which includes a carbide oxynitride-based compound having a composition represented by formula 1: (M1?wRw)uAl1?xSi1+vOzNtCy??formula 1 wherein M is at least one metal element excluding Si and Al, and R is a luminescent central element. w, u, x, v, z, t and y satisfy following relationships: 0.001<w<0.5; 0.66?u?1; 0.07?x?0.73; 0.06?v?0.84; 0.04?z?0.44; 2.7?t?3.1; and 0.019?y?0.13.

Abstract: To provide a sintered silicon nitride with conductivity and densification, an oxide of titanium group elements, such as titanium oxide, hafnium oxide, zirconium oxide and the like, aluminum oxide and/or aluminum nitride is added as needed to silicon nitride-oxidant of rare-earth elements-aluminum oxide system or silicon nitride-oxide of rare-earth elements-magnesia system, and then specified quantity of carbon nonotube (CNT) is added to the above mixture. CNT generates silicon carbide after the reaction with contiguous or proximal silicon nitride and the like depending on the sintering duration at high temperature. Since silicon carbide is generated along with nanotubes, the silicon carbide functions as conductor with excellent heat resistance, corrosion resistance and the like.

Abstract: A fluorescent substance is provided, with includes a matrix composed of a compound having an AlN polytypoid structure represented by the following general formula (1), and a luminescence center element: (Al, M)a(N, X)b ??(1) wherein, M is at least one metal excluding Al, X is at least one non-metal excluding N, and a and b are positive values.

Abstract: A sliding member formed of sintered silicon nitride shows improvement in strength and abrasion resistance when substantially all the .beta.-phase type fine silicon nitride particles present as a main component in the sintered silicon nitride have major diameters not exceeding 60 .mu.m and aspect ratios of not less than 5 and the aforementioned fine silicon nitride particles have a relative density of not less than 98%.

Abstract: A ceramic with anisotropic thermal conductivity, which has an aluminum nitride polytype layer arranged in a portion of an aluminum-nitride-based sintered body as a thermal barrier.

Abstract: As the aluminum nitride component of a sintering aid for powdered silicon nitride, either a spinel type compound having oxygen dissolved in aluminum nitride to form a solid solution or a poly-type aluminum nitride is used. Since the compound is highly stable in water, it can be effectively used in the form of an aqueous slurry mixture. As the sintering aid, this compound is used as effectively as aluminum nitride.

Abstract: A process for preparing aluminum nitride powder, which comprises mixing (i) aluminum hydroxide powder, (ii) carbon powder or a substance capable of forming carbon powder by heating and (iii) at least one of additives selected from the group consisting of aluminum nitride powder, silicon nitride powder, silicon carbide powder and powder of substances capable of forming the powder corresponding to these powders, and baking the mixture thus obtained in a non-oxidative atmosphere containing nitrogen. The process is useful for preparing aluminum nitride powder having small particle size and small particle size distribution and also having a uniform shape of particles, at a lower temperature and in a shorter period of time.

Abstract: A process for producing readily sinterable aluminum nitride powder, which comprises mixing(i) alumina powder and/or powder of a compound capable of forming alumina by heat treatment,(ii) carbon powder and/or powder of a compound capable of forming carbon by heat treatment, and(iii) powder of at least one compound selected from the group consisting of alkaline earth metal oxides, compounds capable of forming said alkaline earth metal oxides by heat treatment, rare earth element oxides and compounds capable of forming said rare earth element oxides by heat treatment,and calcining the resulting mixture in a nitrogen-containing non-oxidative atmosphere, provides an aluminum nitride powder which is readily sinterable without further mixing with a sintering aid.

Abstract: There is disclosed a method for preparing a coated powder comprising the steps of adding a carbon powder and an aluminum nitride powder to a methylsilicic acid powder or a precursor of the methylsilicic acid and mixing them and then subjecting the resulting mixed powder to a heat treatment in an atmosphere including an inert gas or a carbon component-containing gas in order to coat the aluminum nitride powder with silicon carbide.This invention provides a chemically stable coated powder and a sintered body obtained by employing the coated powder has a good thermal conductivity.