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 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 method for producing a nitride fluorescent material includes preparing fluorescent material core particles having a composition containing Sr, Ca, Eu, Al, Si, and N, in which, when a molar ratio of Al in the composition is 1, a molar ratio of Sr is in a range of 0.45 or more and 1.1 or less, a molar ratio of Ca is in a range of more than 0 and less than 0.55, a molar ratio of Eu is in a range of more than 0 and 0.033 or less, a total molar ratio of Sr, Ca, and Eu is 1.1 or less, a molar ratio of Si is in a range of 0.81 or more and 1.21 or less, and a molar ratio of N is in a range of 2.25 or more and 3.85 or less, subjecting them to a first heat treatment and a second heat treatment.

Abstract: Provided are a method for producing a ceramic sintered body having improved light emission intensity, a ceramic sintered body, and a light emitting device. The method for producing a ceramic sintered body comprises preparing a molded body that contains a nitride fluorescent material having a composition containing: at least one alkaline earth metal element M1 selected from the group consisting of Ba, Sr, Ca, and Mg; at least one metal element M2 selected from the group consisting of Eu, Ce, Tb, and Mn; Si; and N, wherein a total molar ratio of the alkaline earth metal element M1 and the metal element M2 in 1 mol of the composition is 2, a molar ratio of the metal element M2 is a product of 2 and a parameter y and wherein y is in a range of 0.001 or more and less than 0.

Abstract: Provided are a method for producing a ceramic sintered body having improved light emission intensity, a ceramic sintered body, and a light emitting device. The method for producing a ceramic sintered body comprises preparing a molded body that contains a nitride fluorescent material having a composition containing: at least one alkaline earth metal element M1 selected from the group consisting of Ba, Sr, Ca, and Mg; at least one metal element M2 selected from the group consisting of Eu, Ce, Tb, and Mn; Si; and N, wherein a total molar ratio of the alkaline earth metal element M1 and the metal element M2 in 1 mol of the composition is 2, a molar ratio of the metal element M2 is a product of 2 and a parameter y and wherein y is in a range of 0.001 or more and less than 0.

Abstract: A method of producing a silicate fluorescent material, the method includes: providing a raw material mixture that contains an M source containing M, an Mg source, an Eu source, and an Si source, and optionally an Mn source, obtaining at least one core particle comprising a silicate fluorescent composition having a formula: (M1-cEuc)3a(Mg1-dMnd)bSi2O8, in which M is at least one element selected from the group consisting of Ca, Sr, and Ba, and a, b, c, and d are numbers respectively satisfying 0.93?a?1.07, 0.90?b?1.10, 0.016?c?0.090, and 0?d?0.22; using a chemical vapor deposition method, depositing aluminum oxide on surfaces of the at least one core particle; and heat treating at a temperature in a range of 210° C. to 490° C. in an oxygen-containing atmosphere.

Abstract: A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision: (Lu1-p-nLnpCen)3(Al1-mGam)5kO12??(I) wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95?k?1.05, 0.05?m?0.70, 0.002?n?0.050, and 0?p?0.30, respectively.

Abstract: Provided is a rare earth aluminate fluorescent material and a method of producing the same. The rare earth aluminate fluorescent material contains at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb; Ce; Al; and optionally at least one element M1 selected from Ga and Sc, wherein a total molar ratio of the rare earth element Ln and Ce is 3, a total molar ratio of Al and the element M1 is a product of 5 and a parameter k in a range of 0.95 or more and 1.05 or less, and a molar ratio of Ce is a product of a parameter n in a range of 0.003 or more and 0.017 or less and 3, and wherein a light emission peak wavelength ?p (nm) at an excitation wavelength of 450 nm and the parameter n satisfy ?p?1590n+531.

Abstract: Provided are a method of producing an aluminate fluorescent material, an aluminate fluorescent material and a light emitting device. The production method includes heat-treating a mixture prepared by mixing a compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr and Ca, a Mg-containing compound not acting as a flux, a Mn-containing compound, an Al-containing compound, a first flux containing at least one alkali metal element selected from the group consisting of Na, K, Rb and Cs, and a Mg-containing second flux to give an aluminate fluorescent material.

Abstract: Provided is a method for producing a nitride fluorescent material including: preparing a raw material mixture including a hydride containing at least one first alkaline earth metal element, at least one compound containing at least one second alkaline earth metal element and selected from an amide compound and an imide compound, a compound containing europium, a compound containing aluminum, and a compound containing silicon, wherein at least one of the compound containing europium, the compound containing aluminum, and the compound containing silicon is a nitride; and subjecting the raw material mixture to a heat treatment to obtain the nitride fluorescent material.

Abstract: A method for producing a ?-AlON fluorescent material, comprising: preparing a first mixture containing a compound containing Mn, a compound containing Li, a compound containing Mg, an aluminum oxide, and an aluminum nitride, in which the amount of fluorine is 150 ppm by mass or less relative to the total amount of the first mixture excluding fluorine, and subjecting the first mixture to a first heat treatment to obtain a first calcined product having an average particle diameter D1, as measured according to a Fisher Sub-Sieve Sizer method, of 10.

Abstract: Provided are an oxynitride fluorescent material, a light emitting device, and a method for producing an oxynitride fluorescent material. The oxynitride fluorescent material containing a composition represented by the following formula (I): (Ba1?aEua)1?bMbSi2O2+cN2+d (I), wherein in the formula (I), M represents at least one element selected from the group consisting of rare earth elements excluding Eu and Sm; and a, b, c, and d each satisfy 0<a?1.0, 0<b?0.07, ?0.3<c<0.3, and ?0.3<d<0.3.

Abstract: Provided are an aluminate fluorescent material, a light emitting device, and a method for producing an aluminate fluorescent material. The aluminate fluorescent material, having an aluminate composition containing: at least one alkaline earth metal element selected from the group consisting of Ba, Sr, and Ca; Mn; and optionally Eu and/or Mg, wherein the fluorine content in the aluminate fluorescent material is 100 ppm or more and 7,000 ppm or less, and the average particle diameter of the aluminate fluorescent material, which is measured according to a Fisher Sub-Sieve Sizer method, is 8 ?m or more.

Abstract: Provided is an aluminate fluorescent material having a high emission intensity and having a composition containing a first element that contains one or more of Ba and Sr, and a second element that contains Mg and Mn. In the composition, when a molar ratio of Al is 10, a total molar ratio of the first element is a parameter a, a total molar ratio of the second element is a parameter b, a molar ratio of Sr is a product of a parameter m and the parameter a, a molar ratio of Mn is a product of a parameter n and the parameter b. The parameters a and b satisfy 0.5<b<a?0.5b+0.5<1.0, the parameter m satisfies 0?m?1.0, and the parameter n satisfies 0.4?n?0.7.

Abstract: Disclosed are a method of producing an aluminate fluorescent material, such an aluminate fluorescent material, and a light emitting device.

Abstract: A method of producing a nitride fluorescent material including a step of first heat-treating a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and a Si-containing compound, in an atmosphere containing nitrogen to obtain a calcined product of raw materials, and a step of second heat-treating the calcined product of raw materials, a Ba-containing compound, a Si-containing compound, and optionally a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and optionally a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg, in an atmosphere containing nitrogen to obtain a nitride fluorescent material is provided, wherein the ratio of the charge-in molar amount of Ba to the total charge-in molar amount of at least one

Abstract: Provided is a light emitting device capable of realizing an excellent color rendering property.

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: 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.