JP5124101B2 - Alpha-type sialon phosphor, method for producing the same, and lighting apparatus - Google Patents

Abstract

Phosphor that can provide white LED that uses a blue LED or an ultraviolet LED as a light source and that has superior luminous efficiency. This phosphor includes, as a main component, +--type sialon represented by a general expression: (M1)x(M2)y(Si,Al) 12 (O,N) 16 (where M1 is one or more types of elements selected from a group consisting of Li, Mg, Ca, Y, and lanthanide element (except for La and Ce) and M2 is one or more types of elements selected from a group consisting of Ce, Pr, Eu, Tb, Yb, and Er, and 0.3<=X+Y<=1.5 and 0<Y<=0.7 are established and the sialon phosphor consists of a powder having a specific surface area of 0.2 to 0.5m<2>/g.

Description

The present invention relates to an α-type sialon phosphor that is excited by ultraviolet or blue light and emits visible light, a method for manufacturing the α-sialon phosphor, and a lighting fixture using the α-sialon phosphor, and particularly a white LED.

As phosphors, silicates, phosphates, aluminates, and sulfides are used as a base material, and transition metals or rare earth metals are used as emission centers.

On the other hand, white LEDs that are excited by an excitation source having high energy such as ultraviolet light or blue light and emit visible light have been attracting attention and are being developed. However, when the above-described conventional phosphor is applied to this application, there is a problem that the luminance of the phosphor is lowered as a result of being exposed to an excitation source.

Nitride and oxynitride phosphors have recently attracted attention as phosphors with low luminance reduction because they have a stable crystal structure and can shift excitation light and light emission to the longer wavelength side.

As nitride and oxynitride phosphors, α-sialons in which specific rare earth elements are activated are known to have useful fluorescence characteristics, and their application to white LEDs and the like are being studied (patents) Literature 1-5, Non-patent literature 1)
Japanese Patent No. 3668770 JP 2003-336059 A JP 2003-124527 A JP 2003-206481 A JP 2004-186278 A J. et al. W. H. van Krebel "On New Rare-Earth Doped M-Si-Al-O-N Materials", TU Eindhoven, The Netherlands, 145-161 (1998)

The α-type sialon has a specific element (α) between the crystal lattices in order to maintain the electrical neutrality by partially replacing the Si—N bond of the α-type silicon nitride crystal with an Al—N bond and an Al—O bond. Ca and Li, Mg, Y, or a lanthanide metal excluding La and Ce) have a structure in which they enter and dissolve in the lattice. Fluorescence characteristics are exhibited by using a rare earth element as a light emission center for a part of the element that enters and dissolves.

The α-sialon is obtained by firing a mixed powder composed of silicon nitride, aluminum nitride, aluminum oxide if necessary, and oxides of intruding solid solution elements at a high temperature in nitrogen. Various fluorescent characteristics can be obtained depending on the ratio of silicon nitride and aluminum compound, the type of element that enters and dissolves, the ratio of the element that becomes the emission center, and the like. In particular, α-sialon in which Ca and the emission center Eu as a penetrating solid solution element are solidly dissolved is efficiently excited in a wide wavelength range from ultraviolet to blue, and exhibits yellow to orange emission. For this reason, it is expected to be used in white LED applications by combining with a blue light emitting LED having a complementary color relationship.

White requires a combination of a plurality of colors different from monochromatic light, and a general white LED is composed of a combination of an ultraviolet LED or a blue LED and a phosphor that emits visible light using the light as an excitation source. ing. Therefore, in order to improve the efficiency of the white LED, the luminous efficiency of the LED of the ultraviolet LED or the blue LED itself is improved, the efficiency of the phosphor used therefor, and the efficiency of extracting emitted light to the outside Need to be improved. In order to expand the application including the general illumination of the white LED, it is necessary to improve all of these efficiencies.

The phosphor for white LED is generally used by being dispersed as micron-sized particles in a sealing material such as an epoxy resin or a silicone resin. In the case of an α-type sialon phosphor, the particles are secondary particles obtained by sintering a plurality of fine primary particles. Although the size and distribution have been studied, attention has not been paid to the surface properties of the secondary particles.

The present invention has been studied variously with respect to the α-type sialon phosphor, and a white LED having a peak at a wavelength in the range of 540 to 600 nm and excellent luminous efficiency, particularly a white LED excellent in luminous efficiency using a blue LED or an ultraviolet LED as a light source. It was made for the purpose of providing.

The present inventor has studied a phosphor using α-sialon as a base material, and has specified a penetrating solid solution element of α-sialon, a crystal lattice size within an appropriate range, and a surface property of secondary particles. It is found that a phosphor having a peak at a wavelength in the range of 540 to 600 nm and having excellent luminous efficiency can be obtained by smoothing the light, and that a lighting apparatus having excellent luminous characteristics can be obtained using the phosphor. It has come.

In addition, the present inventors have found that the surface smoothness of the secondary particles is improved by adding seed particles that are the core of grain growth in the raw material powder and using a dense boron nitride crucible in the synthesis process. This has led to the present invention.

That is, the phosphor of the present invention has a general formula: (M1) _x (M2) _y (Si, Al) ₁₂ (O, N) ₁₆ (where M1 is Li, Mg, Ca, Y and a lanthanide element (La and M2 is one or more elements selected from the group consisting of Ce, Pr, Eu, Tb, Yb and Er, and 0.3 ≦ X + Y ≦ 1.5 and 0 <Y ≦ 0.7), which is a powder having an α-sialon as a main component and a specific surface area of 0.2 to 0.5 m ² / g. The α-sialon phosphor, which is the main component of the phosphor of the present invention, is characterized in that the lattice constant a is in the range of 5.80 to 5.88 nm and the lattice constant c is in the range of 5.65 to 5.73 nm. .

Furthermore, when the phosphor of the present invention was evaluated by the powder X-ray diffraction method, the diffraction intensity of the crystal phase other than the α-type sialon was 10% of the diffraction line intensity of the (102) plane of the α-type sialon. It is characterized by the following.

In the phosphor of the present invention, preferably, M1 contains at least Ca, M2 contains at least Eu, and 0 <Y ≦ 0.1, and ultraviolet or visible light having a wavelength of 250 to 500 nm is excited as an excitation source. , The emission characteristics having a peak in the wavelength range of 540 to 600 nm.

The phosphor production method of the present invention is characterized in that the starting material contains 5 to 30% by mass of α-sialon, and preferably has a specific surface area of 0.5 to ² m ² / g. Features. Further, the phosphor production method of the present invention is characterized in that the starting material is filled in a crucible made of boron nitride material having a density of 1.75 g / cm ³ or more, and is fired in a nitriding atmosphere. It is decomposable boron nitride (P-BN).

The present invention is a lighting fixture comprising a light emitting source and a phosphor, wherein at least the phosphor is used.

Compared with the conventional phosphor, the phosphor of the present invention can absorb excitation light efficiently in the grains because the primary particles are large and the particle surface is smooth without changing the secondary particle size. And has excellent light emission characteristics. Moreover, since the lighting fixture of this invention uses the said fluorescent substance, a favorable light emission characteristic is acquired.

Hereinafter, the present invention will be described in detail.

In α-type sialon, a part of Si—N bond in α-type silicon nitride is replaced by Al—N bond and Al—O bond, and a specific cation enters the lattice in order to maintain electrical neutrality. It is a solid solution and is represented by the general formula: M _z (Si, Al) ₁₂ (O, N) ₁₆ . Here, M is an element that can enter the lattice, and is Li, Mg, Ca, Y, and a lanthanide metal (excluding La and Ce). The solid solution amount Z value of M is a numerical value determined by the Al—N bond substitution rate of the Si—N bond.

In order to express the fluorescence characteristics, it is necessary to use a part of M as an element capable of forming a solid solution and serving as an emission center. To obtain a phosphor emitting visible light, Ce, Pr, Eu, Tb, Yb, It is preferable to use Er. If the element that does not contribute to light emission among the elements that enter and dissolve in the lattice is M1, and the element that is the emission center is M2, the general formula is (M1) _x (M2) _y (Si, Al) ₁₂ (O, N ) ₁₆ Here, in order to express the fluorescence characteristics, it is preferable that the range is 0.3 ≦ X + Y ≦ 1.5 and 0 <Y ≦ 0.7.

In general, α-sialon is obtained by heating and reacting a mixed powder composed of silicon nitride, aluminum nitride, aluminum oxide, and an interstitial solid solution element in a high-temperature nitrogen atmosphere. In the process of increasing the temperature, a part of the constituent components forms a liquid phase, and the substance moves through the liquid phase, thereby generating an α-sialon solid solution. For this purpose, the synthesized α-sialon is formed into a powder form by pulverizing it because a plurality of primary particles are sintered to form secondary particles and further a lump.

As a result of studying the relationship between the luminescent properties and the particle properties, the present inventor has obtained the knowledge that the specific surface area sensitive to the state of the presence of fine powder is closely related to the luminescent properties while exhibiting the smoothness of the particle surface. This has led to the present invention.

That is, in the phosphor of the present invention, in addition to the above composition, the specific surface area of the phosphor powder is preferably 0.2 to 0.5 m ² / g. If the specific surface area is more than 0.5 m ² / g, the surface of the particle and light scattering by the fine particles will cause the efficiency of excitation light to be taken into the particles and the light emission characteristics will deteriorate, which is not preferable. Particles with a specific surface area smaller than 0.2 m ² / g are difficult to obtain with isolated primary particles, and can only be realized by densely sintered particles, and the secondary particles are inevitably enormous, resulting in fluorescence from LEDs and the like. Since it deviates greatly from a suitable size as a body, it is not preferable.

In addition, the phosphor of the present invention is mainly composed of α-sialon but forms a grain boundary phase having a different composition at the particle interface and easily forms a crystalline or amorphous second phase. The total composition of the body powder does not necessarily correspond to the solid solution composition of α-sialon. In the α-type sialon crystal, the crystal lattice size increases as the solid solution amount of aluminum and oxygen increases. Therefore, as a result of studying and examining the lattice constant of this α-sialon, good emission characteristics are obtained when the lattice constant a is in the range of 0.780 to 0.788 nm and the lattice constant c is in the range of 0.565 to 0.573 nm. I found out that

In the present invention, from the viewpoint of fluorescence emission, it is desirable that the α-sialon crystal phase contains as much as possible high purity and is preferably composed of a single phase. Even if it is a mixture containing the crystal phase of this, as long as a characteristic is not fallen, it is good. According to the study results of the present inventor, when evaluated by powder X-ray diffraction method, the diffraction intensity of the crystal phase other than α-type sialon is any relative to the diffraction line intensity of the (102) plane of α-type sialon. It is preferable that it is 10% or less. The presence of a crystal phase exceeding 10% is not preferable because the light emission characteristics deteriorate.

When Ca is selected as M1 and Eu as M2 is selected as an element that dissolves in the crystal lattice of the α-sialon, it is irradiated with ultraviolet light or visible light having a wavelength of 250 to 500 nm as an excitation source. A phosphor having a peak in the wavelength range of the range and emitting yellow to orange light is obtained. For example, when a blue LED is used as an excitation source, a white LED can be obtained by mixing yellow light emitted from the phosphor and excitation light. Thus, a phosphor that emits white light such as a white LED is provided. It is preferable because it is possible.

Regarding the element dissolved in the crystal lattice of α-sialon, the atomic weight ratio of Eu serving as the emission center is preferably in the range of 0 <Y ≦ 0.1. If Y exceeds 0.1, concentration quenching occurs due to interference between solid-solved Eu ions, which is not preferable because emission luminance decreases.

As a method for obtaining the phosphor of the present invention, a method for synthesizing α-sialon in which Ca and Eu are dissolved will be described below.

Silicon nitride, aluminum nitride, calcium-containing compound and europium oxide powder are used as raw materials. The phosphor production method of the present invention is characterized in that 5 to 30% by mass of α-sialon powder synthesized in advance is contained in the raw material powder blended so as to have a predetermined composition. .

The α-sialon powder previously blended with the raw material powder selectively becomes the starting point of grain formation during the heat treatment, promotes the growth of primary particles, and leads to coarsening of primary particles and improvement of surface smoothness. Further, the addition of α-sialon powder to the raw material powder in advance has an effect of suppressing sintering during the synthesis process, and it is possible to produce easily pulverizable sialon. This sialon does not require excessive pulverization, and a powder having a desired particle size can be obtained by a simple pulverization process, and has the effect of suppressing the generation of fine particles accompanying the pulverization process that lowers the light emission characteristics.

If the amount of α-sialon powder added is 5% by mass or more, the specific surface area does not progress in the formation and sintering of new α-sialon particles and the growth of grains in portions other than the added α-sialon particles. Small powder can be obtained. If the amount of α-sialon powder added is 30% by mass or less, it is preferable because there are too many base points for grain growth, and the growth of individual particles becomes small, making it difficult to obtain a sufficiently smooth particle surface. .

The constituent elements and composition of α-sialon powder previously contained in the raw material are not limited. This is because in the excitation of ultraviolet light to blue light, the fluorescence characteristics are expressed mainly in a region close to the powder surface. However, the use of α-sialon powder containing different luminescent center elements or containing impurity elements such as iron that inhibits light emission greatly affects the characteristics of the α-sialon phosphor layer formed on the surface. Therefore, it is not preferable.

In the present invention, it is preferable that the specific surface area of the α-sialon powder added in advance is 0.5 to ² m ² / g. If the specific surface area is 2 m ² / g or less, the effect on the grain growth is sufficiently achieved, while if the specific surface area is 0.5 m ² / g or more, the secondary particle diameter of the synthetic powder is remarkably large. Thus, the final specific surface area of 0.2 to 0.5 m ² / g can be easily obtained without finally requiring a pulverization treatment or the like, which is preferable.

As a method of mixing each raw material containing the α-sialon described above, a method of dry mixing, a method of removing the solvent after wet mixing in an inert solvent that does not substantially react with each component of the raw material, etc. may be adopted. it can. In addition, as a mixing apparatus, a V-type mixer, a rocking mixer, a ball mill, a vibration mill, etc. are used suitably.

A powder obtained by mixing so as to have a desired composition (hereinafter simply referred to as a raw material powder) is filled in a container such as a crucible made of boron nitride at least on the surface in contact with the raw material powder, and 1600-1800 in a nitrogen atmosphere. Α-sialon is obtained by heating for a predetermined time in a temperature range of ° C. The reason why boron nitride is used as the container material is that the reactivity with each component of the raw material is very low, but the present inventor has increased the density of boron nitride used in the crucible to make α in the raw material powder. As in the case of adding type sialon powder, it was found that primary particles were enlarged and the surface was smoothed.

The density of boron nitride used in the crucible is preferably 1.75 g / cm ³ or more. When the density is less than 1.75 g / cm ³ , gas permeation in the crucible easily occurs, volatilization of the components contained in the raw material powder filled in the crucible is promoted, and not only compositional deviation occurs but also in the furnace. The existing carbon monoxide gas, cyan gas, etc. penetrate into the crucible and cause reaction with the raw material powder and inhibition of grain growth, which is not preferable. The density of the crucible is preferably as high as possible. In particular, pyrolytic boron nitride (P-BN) produced by a vapor phase method is very dense and is preferably used.

The filling of the raw material powder into the container is preferably as bulky as possible from the viewpoint of suppressing interparticle sintering during heating. Specifically, it is preferable that the bulk density when filling the raw material powder into the synthesis container is 1.0 g / cm ³ or less.

When the temperature of the heat treatment is 1600 ° C. or higher, there are many unreacted products or the primary particle growth is insufficient, and if it is 1800 ° C. or lower, sintering between particles is remarkable. It will never be.

Regarding the heating time in the heat treatment, a time range is selected in which there is no inconvenience that many unreacted substances are present, primary particles are insufficiently grown, or sintering between particles occurs. According to a person's examination, about 2 to 24 hours is a preferable range.

Since the α-sialon obtained by the above-described operation is in the form of a lump, this is combined with pulverization, pulverization, and, in some cases, classification treatment to form a powder of a predetermined size, and becomes a powdery phosphor applicable to various uses.

In order to use suitably as a fluorescent substance for white LED, it is preferable to make the average particle diameter of a secondary particle into 3-30 micrometers. If the average particle size of the secondary particles is 3 μm or more, the light emission intensity is not lowered, and if the average particle size is 30 μm or less, uniform dispersion to the resin for sealing the LED is easy, and the light emission intensity and color tone. It can be used practically without causing any variation.

The agglomerates made of α-sialon obtained by the above-mentioned production method are relatively easy to grind and show characteristics that can be easily pulverized to a predetermined particle size with a mortar or the like, but are generally used for ball mills, vibration mills, jet mills, etc. Of course, it is acceptable to use a simple grinder.

The phosphor of the present invention has a wide excitation range from ultraviolet to visible light, and emits visible light, and thus is suitable for a lighting fixture. In particular, the phosphor obtained by selecting Ca and Eu as the intrusion elements into the crystal lattice of α-sialon has a peak wavelength due to the substitution rate of Si—N bonds to Al—N bonds and Al—O bonds. It can be controlled to yellow to orange light of 540 to 600 nm and has high luminance light emission characteristics. Therefore, there is a feature that white light can be easily obtained by combination with the blue LED. In addition, α-sialon does not deteriorate even when exposed to high temperatures, has excellent heat resistance, and has excellent long-term stability in an oxidizing atmosphere and moisture environment.

The lighting fixture of this invention is comprised using the light-emitting light source and the fluorescent substance of this invention at least. Examples of the lighting fixture of the present invention include LED lighting fixtures, fluorescent lamps, and the like. For example, the lighting fixture can be formed by a known method as described in JP-A-5-152609, JP-A-7-099345, and the like. An LED lighting apparatus can be manufactured using the phosphor of the invention. In this case, the light emitting light source is preferably an ultraviolet LED or a blue LED that emits light having a wavelength of 350 to 500 nm. These light emitting elements are made of a nitride semiconductor such as GaN or InGaN, and the composition is adjusted. By doing so, it can be a light emitting light source that emits light at a predetermined wavelength.

In addition to the method of using the phosphor of the present invention alone in a lighting fixture, a lighting fixture that emits a desired color can be configured by using it together with a phosphor having other light emission characteristics.

Next, based on an Example and a comparative example, this invention is demonstrated still in detail.

(Examples 1-3, Comparative Examples 1-2)
(Synthesis of α-sialon powder (hereinafter referred to as α-nuclear powder) to be contained in the raw material powder)
The composition of the raw material powder is 75.4% by mass of silicon nitride powder, 14% by mass of aluminum nitride powder, 5.5% by mass of calcium carbonate powder, 4.3% by mass of calcium fluoride powder, and europium oxide powder. Was 0.8 mass%. This raw material powder was wet ball milled for 3 hours in an ethanol solvent with a silicon nitride pot and balls, filtered and dried to obtain a mixed powder.

Next, after passing the mixed powder through a sieve having an opening of 75 μm, it is filled in a boron nitride crucible (manufactured by Denki Kagaku Kogyo Co., Ltd., N1 grade), and in an electric furnace of a carbon heater in atmospheric pressure nitrogen at 1700 ° C. for 5 hours. The heat treatment was performed. The obtained product was lightly crushed and passed through a sieve having an opening of 45 μm to obtain α core powder A.

Part of the α nucleus powder A was further subjected to wet ball milling with a silicon nitride pot and balls for 24 hours in an ethanol solvent, filtered and dried to obtain α nucleus powder B.

The specific surface areas of the α-sialon powder and the α-sialon fine powder were measured by a constant volume gas adsorption method using a specific surface area measuring apparatus (BELSORP-mini) manufactured by Nippon Bell Co., Ltd. and calculated by BET multipoint analysis. The measurement sample was previously subjected to deaeration treatment at 305 ° C. for 2 hours or more in an atmospheric pressure N ₂ flow. N ₂ was used as the adsorbate, and its molecular cross-sectional area was 16.2 × 10 ⁻²⁰ m ² . The specific surface area obtained in this manner, alpha kernel powder A is 0.70 m ² / g, the alpha kernel powder B was 3.9 m ² / g.

(Synthesis of α-type sialon phosphor)
As the raw material powder, the α nucleus powder A or α nucleus powder B, silicon nitride powder, aluminum nitride powder, calcium carbonate powder, and europium oxide powder are used, and are shown in Table 1 so as to become an α-sialon single phase after synthesis. Formulated.

The blended raw material powder is wet ball milled using ethanol as a solvent and a plastic pot and silicon nitride balls, and the solvent is removed by a rotary evaporator, and the mixture powder is passed through a sieve with an opening of 75 μm. Obtained.

About 20 g of the mixed powder is filled into a boron nitride crucible (made by Denki Kagaku Kogyo, NB1000 grade, density 1.5 g / cm ³ , wall thickness 5 mm) having an inner diameter of 60 mm and a height of 35 mm. Then, in a carbon heater electric furnace, heat treatment was performed at 1750 ° C. for 12 hours in a 0.45 MPa pressurized nitrogen atmosphere. The obtained sample was subjected to sieving without pulverization or the like, and the powder finally passing through a sieve having an opening of 45 μm was used as the final product. Under the present circumstances, the value (screening rate) which remove | divided the amount of final product substances by the total mass which performed the sieve classification process was calculated | required as a parameter | index showing the easily grindability of a composite.

(Evaluation of phosphor powder)
・ Specific surface area: Measured by the above method. ・ Checks the crystal phase present in the synthetic powder by powder X-ray diffraction measurement using CuKα rays, and uses Si powder as an internal standard to measure the lattice constant in accordance with JIS K0131. The lattice constant a and the lattice constant c of the α-type sialon hexagonal crystal were calculated.
Fluorescence characteristics: Fluorescence spectrum measurement at 455 nm excitation light is performed using a spectrofluorometer (F4500, manufactured by Hitachi High-Technologies Corporation) calibrated using the rhodamine B method and a standard light source, and the peak wavelength, peak intensity, and luminance are measured. Asked. Both peak intensity and luminance are shown as relative values when Example 1 is set to 100. Moreover, CIE1931 chromaticity coordinate value (x, y) was calculated | required from the fluorescence spectrum.
The evaluation results are shown in Tables 2 and 3.

(Comparative Example 3)
The synthesis was performed under exactly the same conditions as in Example 1 except that the heat treatment temperature was 1500 ° C. The sieve passing rate was 90%, and the specific surface area was 1.20 m ² / g. As a result of X-ray diffraction, it was confirmed that unreacted α-Si ₃ N ₄ and AlN exist as the second crystal phase. The ratio of the strongest peak intensity of α-Si ₃ N ₄ and AlN to the (102) plane diffraction line intensity of α-sialon was 32% and 6%, respectively. When the phosphor was excited at 455 nm, the peak wavelength of the fluorescence spectrum was 576 nm, and the relative peak intensity was as low as 38%.

(Examples 4 to 5)
The BN crucible has a density of 1.5 g / cm ³ in Comparative Example 1; in Example 4, the density is 1.75 g / cm ³ (manufactured by Denki Kagaku Kogyo; N-1 grade); .17 g / cm ³ (Shin-Etsu Chemical Co., P-BN) was used for synthesis. The evaluation results are shown in Tables 4 and 5.

Even if the material of the BN crucible was changed, the sinterability of the composite was not changed and the passing rate of the sieve was low. However, by using a high-density BN crucible, the primary particle diameter was increased and the specific surface area was decreased. As a result, the light emission characteristics were improved as compared with Comparative Example 1.

According to the α-sialon powder and the method for producing the same of the present invention, a phosphor excellent in emission characteristics can be produced with good reproducibility and mass productivity. Since the α-sialon phosphor of the present invention exhibits a light emission characteristic having a peak in the region of 540 to 600 nm by excitation light of ultraviolet to blue light, it is a lighting fixture using ultraviolet light or blue light as a light source, particularly ultraviolet LED or blue light. It is suitable as a phosphor for a white LED using an LED as a light emitting light source, and is very useful industrially.

Moreover, since the lighting fixture of this invention uses the said fluorescent substance, it has the outstanding light emission characteristic, its energy efficiency is high, and it is very useful industrially.

Claims (7)

General formula: (M1) _x (M2) _y (Si, Al) ₁₂ (O, N) ₁₆ (where M1 is selected from the group consisting of Li, Mg, Ca, Y and lanthanide elements (excluding La and Ce)) M2 is one or more elements selected from the group consisting of Ce, Pr, Eu, Tb, Yb and Er, and 0.3 ≦ X + Y ≦ 1.5 and 0 <Y ≦ 0.7) is a phosphor production method for producing a phosphor , characterized in that it is a powder having an α-sialon as a main component and a specific surface area of 0.2 to 0.5 m ² / g. The phosphor is filled in a crucible made of a boron nitride material having a density of 1.75 g / cm ³ or more and fired in a nitriding atmosphere. It is a manufacturing method of the fluorescent substance of Claim 1, Comprising: The α-sialon of the manufactured fluorescent substance has a lattice constant a of 0.780 to 0.788 nm and a lattice constant c of 0.565 to 0.573 nm. A method for producing a phosphor , characterized by being in the range. The method for producing a phosphor according to claim 1 or 2, wherein when the produced phosphor is evaluated by a powder X-ray diffraction method, the diffraction intensity of a crystal phase other than α-sialon is A method for producing a phosphor , characterized in that the intensity of diffraction lines on the (102) plane of α-sialon is 10% or less. 4. The method of manufacturing a phosphor according to claim 1, wherein the manufactured phosphor includes M2 containing at least Eu, and 0 <Y ≦ 0.1, 250 A phosphor production method characterized by exhibiting emission characteristics having a peak in a wavelength range of 540 to 600 nm by irradiating ultraviolet light or visible light having a wavelength of ˜500 nm as an excitation source . The method for producing a phosphor according to any one of claims 1 to 4, wherein the starting material contains 5 to 30% by mass of α-sialon. Specific surface area of α-sialon contained in starting material is 0.5-2m ² The method for producing a phosphor according to claim 5, wherein / g. The method for manufacturing a phosphor according to any one of claims 1 to 6, wherein the crucible is made of pyrolytic boron nitride.