JPH0860147A - Aluminate fluorescent substance - Google Patents

Abstract

PURPOSE: To obatin the fluorescent substance activated with a specific bivalent Eu (and a bivalent Mn), containing an inorganic compound capable of showing a specific X-rays diffraction pattern, hardly lowering the luminous intensity during the lighting, and useful for a three-wavelength range light emitting type fluorescent lump showing a high brightness and high color rendering properties for a long period. CONSTITUTION: This alminate fluorescent substance comprises containing (A) Ba, Sr and Ca, (B) Eu, (C) Mg and Zn, (D) as necessary, Mn and (E) Al, and a crystalline inorganic compound not having the diffraction peak independent of that of the Miller indices 110 at the position of the Miller indices 008 in a powder X-ray diffraction pattern derived by the incidence of a CuKα1 characteristic X-ray [e.g., an aluminate fluorescent substance of the formula (M<1> is the component A; M<2> is the component C;o<(a)<=2; 0<(x)<1; 0<=(y)<1)].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bivalent europium-activated aluminate phosphor or a divalent europium and divalent manganese co-activated aluminate phosphor, and in particular, this phosphor emits light in a three-wavelength region. Shaped fluorescent lamp.

[0002]

2. Description of the Related Art Recently, in the field of fluorescent lamps for general illumination, a three-wavelength band emission type fluorescent lamp has been developed and put into practical use. The phosphor used for this lamp is a mixture of three types of light-emitting phosphors of blue, green and red having a relatively narrow band emission spectrum distribution in an appropriate ratio,
It has high efficiency and high color rendering. Recently, in addition to these three types of phosphors, blue-green phosphors and deep-red phosphors have been put to practical use in a three-wavelength band emission type fluorescent lamp.

In this three-wavelength band emission type fluorescent lamp, when the light output of each phosphor decreases and the change of the emission color during the lamp is large, the balance between the light output and the emission color is disturbed between the phosphors. , Is known to cause a color shift phenomenon. Aluminate phosphors that are activated by divalent europium or co-activated by divalent europium and manganese have high emission efficiency when excited by ultraviolet rays (see Japanese Patent Publication No. 52-22836), and three-wavelength region emission type. Often used as blue and blue-green emitting phosphors in fluorescent lamps (JOU
RNAL OF ELECTROCHEMICAL S
OCIETY 121 (1974) 1627-163
1).

However, a fluorescent lamp using this phosphor as a blue component of a three-wavelength band emission type fluorescent lamp has a drawback that the above-mentioned color shift is large. As a method for solving this problem, the composition of the aluminate phosphor is limited to an extremely narrow range (JP-A-3-106987), and a small amount of manganese is added (JP-A-3-106988). However, further improvement is desired.

Further, the amount of Eu added should be increased (Proceedings of Phosphors Society of Japan, Proceedings 180 (1980) 19-25, Z.P.
hys. Chem. 271 (1990) 1181-11
90) is also a means for improving this drawback, but impurities such as EuAlO ₃ will precipitate if the reduction firing conditions are not appropriate, so that despite the large amount of expensive Eu being used, However, the effect of improving the color misregistration was small.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a divalent europium or a divalent europium and divalent manganese co-activated aluminate phosphor with a small decrease in emission intensity when the fluorescent lamp is turned on.

[0007]

As a method for solving the problem of color misregistration, the present inventors have detailed information on divalent europium or divalent europium and divalent manganese co-activated aluminate phosphors. As a result of the investigation, it was found that the specific aluminate phosphor showed a small decrease in emission intensity when the fluorescent lamp was turned on, and the present invention was accomplished.

That is, the gist of the present invention is to provide at least one element selected from the group consisting of Ba, Sr and Ca,
An aluminate phosphor containing Eu, Mg and / or Zn, and optionally Mn, and Al, and Cu
In a powder X-ray diffraction pattern obtained when Kα ₁ characteristic X-rays are incident, a crystalline inorganic compound having no peak independent of the diffraction peak of Miller index 110 at the position of Miller index 008 is contained. It exists in the aluminate phosphor that is used.

The present invention will be described in detail below. The aluminate phosphor of the present invention comprises at least one element selected from the group consisting of Ba, Sr and Ca, Eu, Mg.
And / or Zn, and optionally Mn, and Al, which is an aluminate phosphor, and the position of the Miller index 008 in the powder X-ray diffraction pattern obtained when CuKα ₁ characteristic X-rays are incident. To a crystalline inorganic compound having no peak independent of the diffraction peak of Miller index 110, and the crystalline inorganic compound has a general formula

[0010]

[Equation 7] (M ¹ _1-x , Eu _x ) O · a (M ² _1-y , M
n _y ) O · (5.5-0.5a) Al ₂ O ₃

(Wherein M ¹ represents at least one element selected from the group consisting of Ba, Sr and Ca, and M ²
Represents Mg and / or Zn, a represents a real number of 0 <a ≦ 2, and x and y represent real numbers of 0 <x <1 and 0 ≦ y <1, respectively) It is preferably the body.

The preferred values of a, x and y in the above general formula are determined for the following reasons. x is 0 in terms of crystal structure
It is variable from 1 to 1, but sufficient emission intensity can be obtained, and moreover, 0.1 or more and 0.5 or less is effective for preventing the reduction of the emission intensity when the fluorescent lamp is turned on. If x is less than 0.1 or exceeds 0.5, the emission intensity will be low. Above all, if x is less than 0.15, the effect of preventing a decrease in emission intensity is small, but if 0.1 ≦ x ≦ 0.15, M in the formula is
The composition ratio of the element of ¹ is 0.2 ≦ Sr / (Ba + Sr + Ca
A composition satisfying + Eu) <1 is effective for preventing a decrease in emission intensity when the fluorescent lamp is turned on. Larger x is more effective in preventing the emission intensity from decreasing, but if it exceeds 0.5, EuAl
Precipitation of O ₃ becomes remarkable, and the effect of preventing deterioration is saturated. y
The crystal structure is variable from 0 to 1, but sufficient emission intensity can be obtained at 0.2 or less, particularly y = 0.
Is also preferable. Further, M ¹ is at least ^one of Ba, Sr, and Ca, but the composition ratio of Ca is 0.01 ≦ Ca.
When the chemical composition is in the range of / (M ¹ + Eu) ≦ 0.17, it is possible to reduce the phosphor synthesis temperature without generating impurities. On the other hand, the composition ratio of Ca is 0.17 <Ca / (M ¹ +
When the chemical composition is in the range of Eu), impurities, which are non-luminous substances, are conspicuously mixed, leading to a decrease in emission intensity.

The space group of the crystalline inorganic compound contained in the phosphor of the present invention is usually P6 ₃ / mmc. The space group is determined by an electron diffraction method, an X-ray diffraction method, a neutron diffraction method, or the like. In order to obtain a phosphor with a good color tone,
The crystalline inorganic compound contained therein has a lattice constant a of 5.
62 <a <5.65Å, lattice constant c is 22.50 <c <
It must be a value that satisfies 22.65Å, but the smaller the lattice constant c within this range, the smaller the decrease in emission intensity when the fluorescent lamp is turned on. When the addition amount of Ba having a large ionic radius is decreased and the addition amount of Eu and Sr having a small ionic radius is increased, the lattice constant c becomes small.

The atomic positions of the elements constituting the crystalline inorganic compound contained in the phosphor of the present invention are determined by the Rietveld analysis method based on the powder X-ray diffraction pattern. It is analyzed by occupying the atomic coordinate positions shown in 2. Eu occupies the same position as the alkaline earth metal M ¹ . On the other hand, Mn occupies the same position as M ² . If Eu and Sr having a small ionic radius are replaced by the position of the alkaline earth metal M ¹ instead of Ba having a large ionic radius, the void of this seat becomes small and the deterioration preventing effect becomes large. There are two possible positions occupied by M ² and Mn. When occupying the 4f seat, a takes a value in the range of 1 ≦ a ≦ 2, and when occupying the 2a seat, a = 1. .
In the case of a <1, Eu emits green light significantly, and it tends to be difficult to obtain blue or blue-green with good color purity. The lattice constant and atomic position are determined by the various diffraction methods described above.

The powder X-ray diffraction pattern from the crystalline inorganic compound having this crystal structure is, for example, (Ba _0.8 , Eu).
_0.2 ) O ・ MgO ・ 5Al ₂ O ₃ composition
, But Al ₂ O ₃ and MgAl ₂ O
_{When a} transparent impurity such as _{4 which} has almost no adverse effect on the light emission is mixed in the phosphor, the diffraction peak of the impurity is added to the pattern in addition to the above diffraction peak.

Powder X-ray diffraction pattern when a CuKα ₁ characteristic X-ray generated from a copper cathode X-ray tube is incident on the crystalline inorganic compound contained in the phosphor of the present invention, which is less likely to deteriorate during lighting of a fluorescent lamp. In Fig. 1, the diffraction peak of the Miller index 008 is independent of the diffraction peak of the Miller index 110 and shows a pattern having no maximum value. On the other hand, when it has a maximum value, the powder X-ray diffraction pattern is as shown in FIG. Here, if the X-ray diffraction intensity is I and the diffraction angle 2θ is t degrees, it means that the primary differential value dI / dt is the Miller index 00 when the X-ray diffraction intensity is I.
It means that there is no negative value between the diffraction peak of 8 and the diffraction peak of Miller index 110. In order to prevent deterioration of the crystalline inorganic compound during lighting of the fluorescent lamp, it is necessary to stabilize the position of oxygen in the Ba—O layer in the crystal, which is perpendicular to the c-axis. For that purpose, it is necessary to shorten the lattice constant c to a value satisfying 22.50 <c <22.65Å. The fact that the lattice constant c is short is based on the same phenomenon as the fact that the diffraction peak of Miller index 008 exists on the high angle side.
This leads to stabilization of the position of oxygen in the O layer. On the other hand, the diffraction peak position of the Miller index 110 has no correlation with the shortening of the lattice constant c. Therefore, the fact that the first-order differential value dI / dt does not have a negative value between the diffraction peak of the mirror index 008 and the diffraction peak of the mirror index 110 means that the lattice constant c is short and the emission intensity when the fluorescent lamp is turned on. Qualitatively means that there is little decrease in.

The phosphor of the present invention can be synthesized as follows. (1) Barium compounds such as barium oxide, barium hydroxide and barium carbonate (2) Strontium compounds such as strontium oxide, strontium hydroxide and strontium carbonate (3) Calcium oxide, calcium hydroxide and calcium carbonate (4) Europium compounds such as europium oxide and europium fluoride (5) Magnesium compounds such as magnesium oxide, magnesium hydroxide and magnesium carbonate (6) Zinc compounds such as zinc oxide, zinc hydroxide and zinc carbonate (7) ) Manganese compounds such as manganese oxide, manganese hydroxide and manganese carbonate (8) Weigh a predetermined amount of aluminum compounds such as aluminum oxide and aluminum hydroxide and apply a flux such as barium fluoride, aluminum fluoride or magnesium fluoride. Combined, thoroughly mixed raw material mixture. The obtained mixture was filled in a crucible and was heated at 1200 to 1700 ° C. for 2 to 4 in a reducing atmosphere.
Bake once or more over 0 hours. The higher the firing temperature,
It is possible to obtain a phosphor with high emission intensity,
If the temperature exceeds ℃, the firing cost does not match the effect of increasing the emission intensity. As a method of obtaining a reducing atmosphere, a method of embedding a crucible filled with a raw material in a crucible filled with carbon,
There is a method in which a lump of graphite or a carbon substance such as coconut husk is put in a crucible filled with a raw material. In order to ensure the reduction, these crucibles may be fired in an atmosphere of nitrogen or nitrogen hydrogen. Water vapor may be contained in these atmospheres. Appropriate reduction baking conditions are very important for producing the phosphor of the present invention. That is, the phosphor of the present invention can be manufactured only by strongly reducing with carbon or carbon monoxide in all stages from the start to the end of firing. The calcined product is dispersed, washed with water, dried and sieved to obtain the blue or blue-green light emitting aluminate phosphor of the present invention.

In the present invention, it is possible to obtain an aluminate phosphor having a luminescence intensity maintenance rate of 92% or more, preferably 94% or more in an X-ray irradiation test. With the conventional aluminate phosphor, only about 90% can be obtained in the X-ray irradiation test, but the phosphor of the present invention has an extremely high emission intensity maintenance rate. General formula

[0019]

[Equation 8] (M ¹ _1-x , Eu _x ) O · a (M ² _1-y , M
n _y ) O · (5.5-0.5a) Al ₂ O ₃ (In the formula, M ¹ represents at least one element selected from the group consisting of Ba, Sr, and Ca, and M ² represents Mg and / or
Or Zn)),

[0020]

[Equation 9] 1 ≦ a ≦ 2 0.1 ≦ x ≦ 0.5 A value satisfying 0 ≦ y ≦ 0.2, and in the case of 0.1 ≦ x ≦ 0.15, further equation When the composition ratio of the element of medium M ¹ satisfies 0.2 ≦ Sr / (Ba + Sr + Ca + Eu) <1, a high emission intensity maintenance rate is achieved.

The X-ray irradiation test was carried out at an accelerating voltage of 40 kV in a powder X-ray diffractometer using a copper cathode tube as an X-ray source at an acceleration voltage of 30 kV.
After irradiating a sample 18.5 cm away from the copper cathode with white X-rays generated when a current of mA was applied for 6 hours,
It is carried out by measuring the luminescence intensity due to the excitation of 53.7 nm ultraviolet light and calculating it as the maintenance ratio with respect to the luminescence intensity before irradiation. In other words, let I _i be the emission intensity of the ultraviolet ray excitation before X-ray irradiation and I _f be the X-ray emission intensity after X-ray irradiation.
The emission intensity maintenance rate Mx after the line irradiation is Mx = 100 × _If
/ I _i %. This X-ray irradiation test has a good correlation with the maintenance rate of the emission intensity when the fluorescent lamp is turned on.

FIG. 3 shows (Ba _1-x , Eu _x ) O.MgO
· 5Al ₂ O ₃ (where, 0 <x ≦ 0.5) after X-ray irradiation test of a phosphor prepared in formulating the composition of the emission intensity maintaining ratio Mx
Is shown. FIG. 4 shows (Ba _0.9-Z Sr _z Eu
_0.1 ) O.MgO.5Al ₂ O ₃ (where 0 ≦ z ≦ 0.
4 shows the emission intensity maintenance rate Mx of the phosphor prepared with the formulation 4) after the X-ray irradiation test. The application of the phosphor of the present invention is effective for a substance that can emit light by ultraviolet excitation, and is not limited to a fluorescent lamp. For example, it can be applied to a plasma display and a rare gas discharge lamp.

[0023]

The divalent europium or 2 according to the present invention
By using a valent europium and a divalent manganese co-activated aluminate phosphor, it becomes possible to manufacture a fluorescent lamp with a small decrease in emission intensity during lighting. Therefore, it becomes possible to manufacture a three-wavelength band emission type fluorescent lamp which exhibits high brightness and high color rendering properties for a long time. Therefore, it is possible to obtain a three-wavelength band emission type fluorescent lamp which exhibits high brightness and high color rendering properties for a long time.

[0024]

Embodiments of the present invention will be described below. Example 1

[0025]

TABLE 1 _{BaCO 3: 0.8mol Eu 2 O 3} : 0.1mol MgO: 1.0mol Al 2 O 3 ( gamma type): 5.0 mol

The above raw materials were wet mixed with ethanol, dried, and molded into pellets at a molding pressure of 1000 kgf / cm ² , put into a crucible and covered with a lid, and the crucible was covered with another charcoal. It was put in a crucible, covered with a lid, and baked in the air at a maximum temperature of 1500 ° C. for 4 hours. Then, the obtained fired pellets are crushed to obtain (Ba _0.8 , Eu _0.2 ) O.
A divalent europium activated blue light emitting barium magnesium aluminate phosphor of MgO · 5Al ₂ O ₃ was obtained.

The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test was 94.8%. The space group of this phosphor is P6 ₃ / mmc, the lattice constant is a = 5.636Å,
c = 22.643Å, and the constituent elements occupied the atomic coordinate positions shown in Table 1 or Table 2. The powder X-ray diffraction pattern of FIG. 1 was shown when CuKα ₁ characteristic X-rays were incident, and a pattern having no peak independent of the diffraction peak of Miller index 110 was shown at the position of Miller index 008.

Examples 2 to 9 As shown in Table 4, an aluminate phosphor was obtained according to Example 1 except that the raw material mixture composition, the firing temperature, and the presence or absence of the addition of AlF ₃ which was a flux were changed. X of these phosphors
Table 5 shows the emission intensity maintenance rate Mx after the line irradiation test. The lattice constants of the main examples are also shown. The space group of these phosphors, the atomic coordinate positions of the constituent elements, and the powder X-ray diffraction pattern are almost the same as in Example 1, and a peak independent of the diffraction peak of the Miller index 110 is located at the position of the Miller index 008. The pattern that does not have is shown. Example 1
-The synthesis methods and characteristics of Example 9 are collectively shown in Tables 4 and 5. Example 10

[0029]

[Table 2] _{BaCO 3: 0.8mol Eu 2 O 3} : 0.1mol 3MgCO 3 · Mg (OH) 2: 0.25mol Al 2 O 3 ( gamma type): 5.0mol AlF _3: 0.012mol

The above raw materials are dry mixed, dried and sieved,
The crucible was filled, and the crucible containing the bead charcoal was placed on the raw material, and the lid was capped and the primary firing was performed at a maximum temperature of 1450 ° C. for 11 hours including a temperature raising / lowering time in a nitrogen atmosphere containing water vapor. Then, the fired powder is crushed, sieved, and charged again in the crucible,
Further, the crucible containing the bead charcoal was placed, the lid was put on, and the secondary firing was performed for 11 hours at a maximum temperature of 1450 ° C. in a nitrogen-hydrogen mixed atmosphere containing water vapor, including a temperature raising / lowering time. Then, the calcined powder is dispersed, washed, dried and sieved, and (B
a _0.8 , Eu _0.2 ) O.MgO.5Al ₂ O ₃ divalent europium activated blue light emitting barium magnesium aluminate phosphor was obtained.

The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test was 94.8%. The space group, lattice constant, atomic coordinate positions of constituent elements, and powder X-ray diffraction pattern of this phosphor were the same as in Example 1. Example 11

[0032]

[Table 3] _{BaCO 3: 0.85mol Eu 2 O 3} : 0.075mol 3MgCO 3 · Mg (OH) 2: 0.25mol Al 2 O 3 ( gamma type): 5.0mol AlF _3: 0.012mol

A barium magnesium aluminate phosphor was obtained according to Example 10 except that the above raw material mixture composition was changed. The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test was 93.1%. The space group, lattice constant, atomic coordinate positions of constituent elements, and powder X-ray diffraction pattern of this phosphor were almost the same as in Example 1. Example 12

[0034]

[Table 4] _{BaCO 3: 0.6mol SrCO 3: 0.2mol} Eu 2 O 3: 0.1mol 3MgCO 3 · Mg (OH) 2: 0.25mol Al 2 O 3 ( gamma type): 5.0mol AlF ₃ : 0.03 mol

A barium strontium magnesium aluminate phosphor was obtained according to Example 10 except that the above raw material mixture composition was changed. The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test was 95.1%. The space group, lattice constant, atomic coordinate positions of constituent elements, and powder X-ray diffraction pattern of this phosphor were almost the same as in Example 1. Comparative Example 1

[0036]

[Table 5] BaCO ₃ : 0.99 mol Eu ₂ O ₃ : 0.005 mol MgO ₃ : 1.0 mol Al ₂ O ₃ (gamma type): 5.0 mol

Example 1 except that the above raw material mixture composition was used.
By the exact same synthesis method, (Ba _0.99, Eu_0.01) O
・ MgO ・ 5Al₂O₃Divalent europium activated blue
A luminescent barium magnesium aluminate phosphor was obtained.
The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test is 7
It was 0.4%. The space group of this phosphor is P6.₃
/ Mmc, the lattice constant is a = 5.636Å, c = 22.6
It was 86Å. CuKα₁Figure when characteristic X-rays are incident
As shown in 2, the Miller index 1 is located at the position of the Miller index 008.
Pattern with 10 diffraction peaks and independent diffraction peaks
showed that.

Comparative Example 2 to Comparative Example 6 As shown in Table 4, an alkaline earth magnesium aluminate phosphor was prepared according to Example 1 except that the raw material mixture composition, the firing temperature, and the presence or absence of addition of AlF ₃ which is a flux were changed. Obtained. Table 5 shows the emission intensity maintenance rate Mx of these phosphors after the X-ray irradiation test. The lattice constants of the main comparative examples are also shown. The powder X-ray diffraction patterns of these phosphors are almost the same as in Comparative Example 1, and the Miller index 00
It had an independent diffraction peak at position 8. Comparative Example 1
-The synthetic methods and characteristics of Comparative Example 6 are collectively shown in Tables 4 and 5. Comparative Example 7

[0039]

[Table 6] BaCO ₃ : 0.90 mol Eu ₂ O ₃ : 0.05 mol 3MgCO ₃ · Mg (OH) ₂ : 0.25 mol Al ₂ O ₃ (gamma type): 5.0 mol AlF ₃ : 0.012 mol

A barium magnesium aluminate phosphor was obtained in accordance with Example 10 except that the above raw material mixture composition was changed. The emission intensity maintenance rate Mx of this phosphor after the X-ray irradiation test was 90.4%. The powder X-ray diffraction pattern of this phosphor was almost the same as that of Comparative Example 1, and had an independent diffraction peak at the position of Miller index 008.

[0041]

[Table 7]

[0042]

[Table 8]

[0043]

[Table 9]

[0044]

[Table 10]

[0045]

[Table 11]

[0046]

[Table 12]

[0047]

[Table 13]

[0048]

[Table 14]

[Brief description of drawings]

FIG. 1 is a powder X-ray diffraction pattern in Example 1.

2 is a powder X-ray diffraction pattern in Comparative Example 1. FIG.

FIG. 3 is (Ba _1-x , Eu _x ) O.MgO.5Al ₂ O
Luminous intensity maintenance rate (0 <x ≦ 0.5) after X-ray irradiation test of the phosphor prepared with the composition of ₃

FIG. 4 is (Ba _0.9-z Sr _z Eu _0.1 ) O.MgO.5
Luminous intensity maintenance rate (0 <z ≦ 0.4) of the phosphor prepared with the composition of Al ₂ O ₃ after the X-ray irradiation test.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chisato Miura 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Takayuki Kusune 1060 Narita, Odawara-shi, Kanagawa In-house (72) Inventor Masakazu Nabe 1060 Narita, Odawara-shi, Kanagawa Kasei Optonix Co., Ltd. (72) Inventor Koichi Toriumi 1060, Narita, Odawara-shi, Kanagawa Kasei Optonix Co., Ltd.

Claims (9)

[Claims] 1. At least one element selected from the group consisting of Ba, Sr and Ca, Eu, Mg and / or Z.
n is an aluminate phosphor containing n, and optionally Mn, and Al, and in the powder X-ray diffraction pattern obtained when CuKα ₁ characteristic X-rays are incident, the mirror index is at the position of mirror index 008. An aluminate phosphor containing a crystalline inorganic compound having no peak independent of the diffraction peak of 110. 2. The crystalline inorganic compound is represented by the general formula: (M ¹ _1-x , Eu _x ) O · a (M ² _1-y , M
n _y ) O · (5.5-0.5a) Al ₂ O ₃ (In the formula, M ¹ represents at least one element selected from the group consisting of Ba, Sr, and Ca, and M ² represents Mg and / or
Or Zn, a represents a real number of 0 <a ≦ 2, and x and y represent a real number of 0 <x <1 and 0 ≦ y <1 respectively). The aluminate phosphor according to claim 1, wherein: 3. The aluminate phosphor according to claim 2, wherein x and y are respectively: 0.1 ≦ x ≦ 0.5 0 ≦ y ≦ 0.2. 4. The aluminate phosphor according to claim 2 or 3, wherein a is a real number satisfying 1 ≦ a ≦ 2. 5. When x is 0.1 ≦ x ≦ 0.15, the composition ratio of the elements of M ¹ satisfies 0.2 ≦ Sr / (Ba + Sr + Ca + Eu) <1. 5. The method according to claim 3 or 4, wherein
The aluminate phosphor described in 1. 6. The method according to claim 2, wherein y = 0.
5. The aluminate phosphor according to any one of items 1 to 5. 7. The aluminate phosphor according to claim 1, which is composed of a single layer of the crystalline inorganic compound. 8. The aluminate phosphor according to any one of claims 1 to 7, wherein a maintenance rate of emission intensity in an X-ray irradiation test is 92% or more. 9. The general formula: (M ¹ _1-x , Eu _x ) O · a (M ² _1-y , M
n _y ) O · (5.5-0.5a) Al ₂ O ₃ (In the formula, M ¹ represents at least one element selected from the group consisting of Ba, Sr, and Ca, and M ² represents Mg and / or
Or Zn, and a, x, and y are each 1 ≦ a ≦
2, 0.1 ≦ x ≦ 0.5, 0 ≦ y ≦ 0.2, where 0.1 ≦ x ≦ 0.15, the composition ratio of M ¹ is 0.2 ≦ Sr / (Ba + Sr + Ca + Eu) <1
Of the aluminate phosphor.