Preparation method and application of compound lanthanum magnesium aluminum sulfate and lanthanum magnesium aluminum sulfate phosphor

Abstract

The present invention relates to a preparation method and application of a compound of lanthanum magnesium aluminum sulfide and lanthanum magnesium aluminum sulfide phosphor. The molecular formula of the compound is LaMg6Al6S 16 , the molecular weight is 958.22, the unit cell parameters are prepared by high temperature solid phase method, the sulfur aluminum magnesium lanthanum phosphor, the molecular formula is LaMg6Al6S 16 The structure belongs to the hexagonal crystal system, the space group is , and the unit cell parameter is . The phosphor prepared by the method of the present invention has good crystallinity, high luminous efficiency, strong brightness, stable chemical properties, and long life. The method is simple and easy to implement, has a wide process window, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to a preparation method and application of a lanthanum magnesium aluminum sulphate compound and lanthanum magnesium aluminum sulphate phosphor, belonging to the technical field of phosphors for LEDs. Background Art

[0002] White light-emitting diodes (WLEDs) based on rare earth doped fluorescent materials have become a widely used new solid-state light source. Due to their high efficiency, energy saving, environmental protection and durability, they have become the best choice in the current lighting field. The current production method of WLEDs is mainly to combine LED chips and phosphors. The most commonly used method is to apply yellow phosphor on the top of the LED chip that emits blue light to prepare white light LEDs. However, with the continuous improvement of living standards, this WLED that lacks red light emission, resulting in white light cooling, low color rendering index and high color temperature, can no longer meet people's demand for high-quality life. Therefore, people have begun to improve LED devices in the following three ways: (1) Let YAG:Ce 3+ The luminescence spectrum of the phosphor is red-shifted, resulting in the presence of red light components in the entire spectrum; (2) doping the original system with red-emitting rare earth ions can also make up for the lack of red light; (3) mixing red, green, and blue phosphors in a certain proportion and then applying them to the near-ultraviolet or ultraviolet LED chip, so that the LED device can emit white light with a high color rendering index and low color temperature. It can be seen that the first two methods are to change the performance of the entire LED device by changing the composition of the phosphor, while the third method is to change the LED chip and phosphor at the same time to obtain ideal LED performance. At the same time, this method is also the mainstream research direction of people today. Therefore, the development of phosphors with excellent luminescence performance is an important prerequisite for the preparation of high-quality WLEDs. Summary of the Invention

[0003] The present invention aims to provide a compound of lanthanum magnesium aluminum sulfate, the chemical formula of which is LaMg6Al6S 16 ;

[0004] Another object of the present invention is to provide a method for preparing the compound aluminum magnesium lanthanum sulphate;

[0005] Another object of the present invention is to provide a method for preparing the aluminum magnesium lanthanum sulfur phosphor;

[0006] Another object of the present invention is to provide uses of the lanthanum magnesium aluminum sulfate phosphor.

[0007] The present invention discloses a compound of lanthanum magnesium aluminum sulfate, the molecular formula of which is LaMg6Al6S 16 , molecular weight is 958.22, unit cell parameters are The high temperature solid phase method is used to prepare the compound lanthanum magnesium aluminum sulfate, which is prepared by the following steps:

[0008] a. According to the chemical formula LaMg6Al6S 16 The molar ratio of La:Mg:Al:S is 1:6:6:16. The raw materials are weighed and mixed under argon, placed in a quartz container, and evacuated to 10 -3 Pa is melt-sealed to obtain a mixture; wherein the La raw material is La or La2S3; the Mg raw material is Mg or MgS; the Al raw material is Al or Al2S3; and the sulfur raw material is S;

[0009] b. The mixture in step a was placed in a muffle furnace, heated to 980-1100°C at a rate of 18-32°C / h, and kept at this temperature for 48-98h; then cooled to room temperature at a rate of 18-32°C / h, removed, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0010] A method for preparing a lanthanum magnesium aluminum sulfate phosphor, wherein the phosphor has the molecular formula LaMg6Al6S 16 , the structure belongs to the hexagonal system, and the space group is The specific operation is as follows:

[0011] a. According to the chemical formula LaMg6Al6S 16 The molar ratio of La:Mg:Al:S is 1:6:6:16. The raw materials are weighed and mixed under argon, placed in a quartz container, and evacuated to 10 -3 Pa is melt-sealed to obtain a mixture; wherein the La raw material is La or La2S3; the Mg raw material is Mg or MgS; the Al raw material is Al or Al2S3; and the sulfur raw material is S;

[0012] b. The mixture in step a was placed in a muffle furnace, heated to 950-1100°C at a rate of 8-45°C / h, and kept at this temperature for 60-140h; then cooled to room temperature at a rate of 4-18°C / h, removed, crushed and ground into a mortar, and sieved to 45-220 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

[0013] The aluminum magnesium lanthanum sulfide phosphor obtained by the method is used in preparing LED lamps.

[0014] The preparation method of the compound aluminum magnesium lanthanum sulfide and the aluminum magnesium lanthanum sulfide phosphor described in the present invention is prepared according to the following chemical reaction formula:

[0015] La+6Mg+6Al+16S=LaMg6Al6S 16 ;

[0016] La2S3+12Mg+12Al+29S=2LaMg6Al6S 16 ;

[0017] La+6MgS+6Al+10S=LaMg6Al6S 16 ;

[0018] La+6Mg+3Al2S3+7S=LaMg6Al6S 16 ;

[0019] La2S3+12MgS+12Al+17S=2LaMg6Al6S 16 ;

[0020] La2S3+12Mg+6Al2S3+11S=2LaMg6Al6S 16 ;

[0021] La+6MgS+3Al2S3+S=LaMg6Al6S 16 . BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The LaMg6Al6S 16 Structural diagram of [LaS6] group, [AlS4] group, and [MgS6] group; (b) [AlS3] chain and [Al2S5] chain; (c) arrangement of [AlS4] group observed along the c direction; (d) ring structure formed by [MgS6] group and [AlS4] group connected by sharing corners and sharing edges along the c direction; (e) [Mg6Al6S 16 ] framework; (f) Arrangement of [LaS6] groups observed along the c direction; (g) Overall three-dimensional structure of the compound observed along the c direction;

[0023] Figure 2 The LaMg6Al6S 16 X-ray diffraction spectrum of

[0024] Figure 3 The LaMg6Al6S 16 Excitation and emission spectra: When excited by ultraviolet light, violet light or blue light, it can produce light ranging from blue-cyan to green-yellow;

[0025] Figure 4 Schematic diagram of the light source of the present invention: 1 is the first wire, 2 is the heat sink, 3 is the light-emitting diode, 4 is the phosphor coating, 5 is the potting glue, 6 is the reflective bowl, 7 is the second wire, and 8 is the gold wire. DETAILED DESCRIPTION

[0026] The present invention is described in detail with reference to the accompanying drawings and embodiments, which are only for helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0027] Example 1

[0028] According to the chemical reaction formula La+6Mg+6Al+16S=LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0029] a. Weigh La, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0030] b. The mixture in step a was placed in a muffle furnace, heated to 1050°C at a rate of 18°C / h, kept constant for 70h, cooled to room temperature at a rate of 20°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0031] Example 2

[0032] According to the chemical reaction formula La2S3+12Mg+12Al+29S=2LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0033] a. Weigh La2S3, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0034] b. The mixture in step a was placed in a muffle furnace, heated to 1080°C at a rate of 25°C / h, kept constant for 85h, then cooled to room temperature at a rate of 30°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0035] Example 3

[0036] According to the chemical reaction formula La+6MgS+6Al+10S=LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0037] a. Weigh La, MgS, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0038] b. The mixture in step a was placed in a muffle furnace, heated to 1000°C at a rate of 27°C / h, kept constant for 90h, then cooled to room temperature at a rate of 18°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of lanthanum magnesium sulfate.

[0039] Example 4

[0040] According to the chemical reaction formula La+6Mg+3Al2S3+7S=LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0041] a. Weigh La, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0042] b. The mixture in step a was placed in a muffle furnace, heated to 1090°C at a rate of 29°C / h, kept constant for 95h, then cooled to room temperature at a rate of 23°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0043] Example 5

[0044] According to the chemical reaction formula La2S3+12MgS+12Al+17S=2LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0045] a. Weigh La2S3; MgS; Al; S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0046] b. The mixture in step a was placed in a muffle furnace, heated to 1000°C at a rate of 20°C / h, kept constant for 55h, then cooled to room temperature at a rate of 29°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0047] Example 6

[0048] According to the chemical reaction formula La2S3+12Mg+6Al2S3+11S=2LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0049] a. Weigh La2S3, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0050] b. Place the mixture in step a in a muffle furnace, heat it to 1000°C at a rate of 18°C / h, keep it at that temperature for 65h, then cool it to room temperature at a rate of 25°C / h, take it out, put it into a mortar and crush it to obtain a pure sample of the compound aluminum magnesium lanthanum sulfate.

[0051] Example 7

[0052] According to the chemical reaction formula La+6MgS+3Al2S3+S=LaMg6Al6S 16 Preparation of compound LaMg6Al6S 16 :

[0053] a. Weigh La, MgS, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0054] b. The mixture in step a was placed in a muffle furnace, heated to 1050°C at a rate of 25°C / h, kept constant for 90h, then cooled to room temperature at a rate of 18°C / h, taken out, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

[0055] Example 8

[0056] According to the chemical reaction formula La+6Mg+6Al+16S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0057] a. Weigh La, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0058] b. The mixture in step a was placed in a muffle furnace, heated to 1100°C at a rate of 15°C / h, kept at this temperature for 120h, cooled to room temperature at a rate of 9°C / h, removed, crushed and ground into a mortar and sieved to 140 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

[0059] Example 9

[0060] According to the chemical reaction formula La2S3+12Mg+12Al+29S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0061] a. Weigh La2S3, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0062] b. The mixture in step a was placed in a muffle furnace, heated to 1085°C at a rate of 36°C / h, kept constant for 150h, then cooled to room temperature at a rate of 14°C / h, taken out, crushed and ground into a mortar and sieved to 100 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0063] Example 10

[0064] According to the chemical reaction formula La+6MgS+6Al+10S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0065] a. Weigh La, MgS, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0066] b. The mixture in step a was placed in a muffle furnace, heated to 1060°C at a rate of 26°C / h, kept at this temperature for 135h, then cooled to room temperature at a rate of 5°C / h, taken out, crushed and ground into a mortar and sieved to 75 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0067] Example 11

[0068] According to the chemical reaction formula La+6Mg+3Al2S3+7S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0069] a. Weigh La, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0070] b. The mixture in step a was placed in a muffle furnace, heated to 1000°C at a rate of 40°C / h, kept at a constant temperature for 115h, then cooled to room temperature at a rate of 17°C / h, taken out, crushed and ground into a mortar and sieved to 90 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0071] Example 12

[0072] According to the chemical reaction formula La2S3+12MgS+12Al+17S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0073] a. Weigh La2S3; MgS; Al; S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0074] b. The mixture in step a was placed in a muffle furnace, heated to 1080°C at a rate of 15°C / h, kept at this temperature for 100h, then cooled to room temperature at a rate of 18°C / h, taken out, crushed and ground into a mortar and sieved to 180 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

[0075] Example 13

[0076] According to the chemical reaction formula La2S3+12Mg+6Al2S3+11S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0077] a. Weigh La2S3, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0078] b. The mixture in step a was placed in a muffle furnace, heated to 1055°C at a rate of 43°C / h, kept constant for 85h, then cooled to room temperature at a rate of 6°C / h, taken out, crushed and ground into a mortar and sieved to 200 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0079] Example 14

[0080] According to the chemical reaction formula La+6MgS+3Al2S3+S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0081] a. Weigh La, MgS, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0082] b. The mixture in step a was placed in a muffle furnace, heated to 990°C at a rate of 24°C / h, kept at this temperature for 96h, then cooled to room temperature at a rate of 10°C / h, taken out, crushed and ground into a mortar and sieved to 190 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0083] Example 15

[0084] According to the chemical reaction formula La+6Mg+6Al+16S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0085] a. According to the reaction formula, weigh La, Mg, Al, and S in argon atmosphere, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0086] b. The mixture in step a was placed in a muffle furnace, heated to 1080°C at a rate of 15°C / h, kept at this temperature for 120h, cooled to room temperature at a rate of 16°C / h, removed, crushed and ground into a mortar and sieved to 85 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0087] Example 16

[0088] According to the chemical reaction formula La2S3+12Mg+12Al+29S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0089] a. Weigh La2S3, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0090] b. The mixture in step a was placed in a muffle furnace, heated to 1050°C at a rate of 39°C / h, kept constant for 95h, then cooled to room temperature at a rate of 5°C / h, removed, crushed and ground into a mortar and sieved to 105 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

[0091] Example 17

[0092] According to the chemical reaction formula La+6MgS+6Al+10S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0093] a. Weigh La, MgS, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0094] b. The mixture in step a was placed in a muffle furnace, heated to 1010°C at a rate of 29°C / h, kept at this temperature for 140h, then cooled to room temperature at a rate of 14°C / h, taken out, crushed and ground into a mortar and sieved to 125 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0095] Example 18

[0096] According to the chemical reaction formula La+6Mg+3Al2S3+7S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0097] a. Weigh La, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0098] b. The mixture in step a was placed in a muffle furnace, heated to 1100°C at a rate of 23°C / h, kept at a constant temperature for 65h, then cooled to room temperature at a rate of 8°C / h, taken out, crushed and ground into a mortar and sieved to 210 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0099] Example 19

[0100] According to the chemical reaction formula La2S3+12MgS+12Al+17S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0101] a. Weigh La2S3; MgS; Al; S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0102] b. The mixture in step a was placed in a muffle furnace, heated to 965°C at a rate of 9°C / h, kept constant for 70h, then cooled to room temperature at a rate of 6°C / h, taken out, crushed and ground into a mortar and sieved to 60 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0103] Example 20

[0104] According to the chemical reaction formula La2S3+12Mg+6Al2S3+11S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0105] a. Weigh La2S3, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0106] b. The mixture in step a was placed in a muffle furnace, heated to 950°C at a rate of 10°C / h, kept constant for 90h, then cooled to room temperature at a rate of 5°C / h, taken out, crushed and ground into a mortar and sieved to 170 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0107] Example 21

[0108] According to the chemical reaction formula La+6MgS+3Al2S3+S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0109] a. Weigh La, MgS, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0110] b. The mixture in step a was placed in a muffle furnace, heated to 1020°C at a rate of 26°C / h, kept at this temperature for 110h, then cooled to room temperature at a rate of 17°C / h, taken out, crushed and ground into a mortar and sieved to 165 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

[0111] Example 22

[0112] According to the chemical reaction formula La+6Mg+6Al+16S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0113] a. Weigh La, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0114] b. The mixture in step a was placed in a muffle furnace, heated to 1090°C at a rate of 45°C / h, kept at this temperature for 140h, cooled to room temperature at a rate of 4°C / h, removed, and crushed into a mortar and ground to 75 mesh to obtain a powdered lanthanum magnesium aluminum sulfate phosphor.

[0115] Example 23

[0116] According to the chemical reaction formula La2S3+12Mg+12Al+29S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0117] a. Weigh La2S3, Mg, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0118] b. The mixture in step a was placed in a muffle furnace, heated to 1060°C at a rate of 35°C / h, kept at this temperature for 90h, then cooled to room temperature at a rate of 18°C / h, taken out, crushed and ground into a mortar and sieved to 110 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0119] Example 24

[0120] According to the chemical reaction formula La+6MgS+6Al+10S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0121] a. Weigh La, MgS, Al, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0122] b. The mixture in step a was placed in a muffle furnace, heated to 1085°C at a rate of 40°C / h, kept constant for 95h, then cooled to room temperature at a rate of 15°C / h, taken out, crushed and ground into a mortar and sieved to 155 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0123] Example 25

[0124] According to the chemical reaction formula La+6Mg+3Al2S3+7S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0125] a. Weigh La, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0126] b. The mixture in step a was placed in a muffle furnace, heated to 960°C at a rate of 20°C / h, kept at this temperature for 80h, then cooled to room temperature at a rate of 11°C / h, taken out, crushed and ground into a mortar and sieved to 75 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0127] Example 26

[0128] According to the chemical reaction formula La2S3+12MgS+12Al+17S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0129] a. Weigh La2S3; MgS; Al; S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0130] b. The mixture in step a was placed in a muffle furnace, heated to 1010°C at a rate of 8°C / h, kept at a constant temperature for 105h, then cooled to room temperature at a rate of 9°C / h, taken out, crushed and ground into a mortar and sieved to 185 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0131] Example 27

[0132] According to the chemical reaction formula La2S3+12Mg+6Al2S3+11S=2LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0133] a. Weigh La2S3, Mg, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0134] b. The mixture in step a was placed in a muffle furnace, heated to 1055°C at a rate of 24°C / h, kept constant for 70h, then cooled to room temperature at a rate of 18°C / h, taken out, crushed and ground into a mortar and sieved to 135 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0135] Example 28

[0136] According to the chemical reaction formula La+6MgS+3Al2S3+S=LaMg6Al6S 16 Preparation of phosphor LaMg6Al6S 16 :

[0137] a. Weigh La, MgS, Al2S3, and S in the reaction ratio under argon, mix them evenly, put the mixture into a quartz container, and evacuate to 10 -3 Pa is melt-sealed to obtain a mixture;

[0138] b. The mixture in step a was placed in a muffle furnace, heated to 1075°C at a rate of 13°C / h, kept at this temperature for 140h, then cooled to room temperature at a rate of 16°C / h, taken out, crushed and ground into a mortar and sieved to 215 mesh to obtain lanthanum magnesium aluminum sulfate phosphor.

[0139] Example 29

[0140] according to Figure 4 As shown, a 405nm blue light emitting diode 3 is fixed on a reflective bowl 6, a heat sink 2 is provided under the reflective bowl 6, the positive electrode of the blue light emitting diode 3 is connected to a first wire 1, and the negative electrode of the light emitting diode 3 is connected to a second wire 7 through a gold wire 8;

[0141] Any of the phosphors LaMg6Al6S obtained in Examples 1-28 16 , mixed with epoxy resin and applied to the blue LED 3 to form a phosphor coating 4. Finally, potting compound 5 is used to protect the phosphor coating 4, the purple LED 3, and the gold wire 8. Testing has shown that this material produces light ranging from bluish-cyan to greenish-yellow when excited by ultraviolet, violet, or blue light.

[0142] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A compound of lanthanum magnesium aluminum sulfate, characterized in that The molecular formula of this compound is LaMg6Al6S 16 , molecular weight is 958.22, unit cell parameters are Made by high temperature solid phase method.

2. A method for preparing the compound aluminum magnesium lanthanum sulphate according to claim 1, characterized in that Follow these steps: a. According to the chemical formula LaMg6Al6S 16 The molar ratio of La:Mg:Al:S is 1:6:6:

16. The raw materials are weighed and mixed under argon, placed in a quartz container, and evacuated to 10 -3 Pa is melt-sealed to obtain a mixture; wherein the La raw material is La or La2S3; the Mg raw material is Mg or MgS; the Al raw material is Al or Al2S3; and the sulfur raw material is S; b. The mixture in step a was placed in a muffle furnace, heated to 980-1100°C at a rate of 18-32°C / h, and kept at this temperature for 48-98h; then cooled to room temperature at a rate of 18-32°C / h, removed, and crushed into a mortar to obtain a pure sample of a powdered compound of aluminum magnesium lanthanum sulfate.

3. A method for preparing a sulphur aluminium magnesium lanthanum phosphor, characterized in that The molecular formula of the phosphor is LaMg6Al6S 16 , the structure belongs to the hexagonal system, and the space group is The specific operation is as follows: a. According to the chemical formula LaMg6Al6S 16 The molar ratio of La:Mg:Al:S is 1:6:6:

16. The raw materials are weighed and mixed under argon, placed in a quartz container, and evacuated to 10 -3 Pa is melt-sealed to obtain a mixture; wherein the La raw material is La or La2S3; the Mg raw material is Mg or MgS; the Al raw material is Al or Al2S3; and the sulfur raw material is S; b. The mixture in step a was placed in a muffle furnace, heated to 950-1100°C at a rate of 8-45°C / h, and kept at this temperature for 60-140h; then cooled to room temperature at a rate of 4-18°C / h, removed, crushed and ground into a mortar, and sieved to 45-220 mesh to obtain a lanthanum magnesium aluminum sulfate phosphor.

4. Use of the sulphur aluminium magnesium lanthanum phosphor obtained by the method according to claim 3 in the preparation of LED lamps.

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