Europium-doped silicate red-blue fluorescent glass-ceramics and preparation method thereof

Abstract

This invention relates to a europium-doped silicate red-blue fluorescent microcrystalline glass and its preparation method. The chemical composition of the europium-doped silicate red-blue fluorescent microcrystalline glass includes: a glass matrix and a dopant, europium oxide (Eu₂O₃); preferably, the crystal phases of the europium-doped silicate red-blue fluorescent microcrystalline glass include labradorite and diopside microcrystalline phases; the chemical composition of the glass matrix includes: 50–60 mol% SiO₂, 10–20 mol% Al₂O₃, 0–10 mol% K₂O, 0–10 mol% Na₂O, 5–30 mol% CaO, 5–30 mol% MgO, and 0–10 mol% TiO₂; the mass of the dopant, europium oxide (Eu₂O₃), is 1–10 wt% of the glass matrix.

Description

Technical Field

[0001] This invention belongs to the field of microcrystalline glass preparation technology, specifically relating to a europium-doped silicate red and blue fluorescent microcrystalline glass and its preparation method. Background Technology

[0002] Sunlight is an essential natural condition for plant growth and development. Plants accumulate necessary nutrients through photosynthesis, but due to seasonality and light variations (such as cloudy days), plants often struggle to obtain sufficient light for photosynthesis. Therefore, supplementing plants with artificial light sources or light-converting methods is an excellent way to promote plant growth. From the perspective of plant photosynthesis, the blue light spectrum (400-500nm) and the red light spectrum (600-700nm) are the peak absorption regions of chlorophyll and play a crucial regulatory role in plant photomorphogenesis. Among them, short-wavelength blue light mainly promotes stomatal differentiation and circadian rhythm regulation, while long-wavelength red light significantly affects photoperiodic response and phytochrome activation.

[0003] Eu 2+ / Eu 3+ The spectra of activated silicate phosphors and fluorescent glasses are highly matched with the effective radiation of plant photosynthesis, providing high-efficiency fluorescent conversion materials for implementing intelligent agricultural lighting systems. Common preparation methods for these fluorescent materials include solid-state synthesis and melt-quenching. However, the preparation of traditional fluorescent materials generally relies on high-temperature heat treatment processes in reducing gas environments such as H2, N2 / H2 mixtures, or CO, resulting in high production costs due to the stringent preparation conditions. Furthermore, in terms of luminescence performance, the luminescence center peak generally has poor matching with the region of the plant absorption spectrum; simultaneously, the mechanical properties are also unsatisfactory. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a europium-doped silicate red and blue fluorescent microcrystalline glass and its preparation method, which gives it good glass-forming ability and crystallization characteristics, as well as excellent chemical stability and mechanical strength.

[0005] In a first aspect, the present invention provides a europium-doped silicate red-blue fluorescent microcrystalline glass, wherein the chemical composition of the europium-doped silicate red-blue fluorescent microcrystalline glass includes: a glass matrix and a dopant europium oxide Eu2O3; preferably, the crystal phase of the europium-doped silicate red-blue fluorescent microcrystalline glass includes labradorite and diopside microcrystalline phases; The chemical composition of the glass matrix includes: 50-60 mol% SiO2, 10-20 mol% Al2O3, 0-10 mol% K2O, 0-10 mol% Na2O, 5-30 mol% CaO, 5-30 mol% MgO, and 0-10 mol% TiO2; the mass of the dopant europium oxide (Eu2O3) is 1-10 wt% of the glass matrix.

[0006] Preferably, the crystallization mechanism of the glass matrix is ​​surface crystallization, and its main crystalline phases are labradorite (Na,Ca)(Al,Si)4O8 and diopside CaMgSi2O6.

[0007] Preferably, the europium-doped silicate red and blue fluorescent microcrystalline glass is a mixed-valence europium ion-doped fluorescent microcrystalline glass, which simultaneously obtains fluorescence of divalent and trivalent europium ions when excited by ultraviolet light at 348 nm, 360 nm, and 393 nm, wherein Eu 2+ The emission wavelength is 410nm, Eu 3+ The center of its emission wavelength is 612nm.

[0008] Preferably, the europium-doped silicate red and blue fluorescent microcrystalline glass begins to crystallize at temperature T. c and glass transition temperature T g The difference between them is ΔT > 150℃.

[0009] Preferably, the activation energy E for crystallization of the europium-doped silicate red and blue fluorescent microcrystalline glass is... a <400KJ / mol.

[0010] Secondly, the present invention provides a method for preparing the above-mentioned europium-doped silicate red and blue fluorescent microcrystalline glass, the preparation method comprising the following steps: (1) Weigh the raw material powder according to the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass and melt it to form a glass liquid; (2) The glass liquid is cast and annealed to obtain silicate red fluorescent glass; (3) The silicate red fluorescent glass is subjected to microcrystallization heat treatment to obtain europium-doped silicate red and blue fluorescent microcrystalline glass.

[0011] Preferably, in step (1), the melting temperature is 1500-1600℃ and the melting time is 2-4 hours.

[0012] Preferably, in step (2), the casting temperature is 300-500℃ and the casting time is 20s-1min.

[0013] Preferably, in step (2), the annealing temperature is 500-700℃ and the holding time is 4-8 hours.

[0014] Preferably, in step (3), the microcrystallization heat treatment process is as follows: the temperature is increased from room temperature to nucleation temperature of 700-750℃ at a heating rate of 2-5℃ / min and held for 30-120 minutes, then the temperature is increased to microcrystallization temperature of 800-1200℃ at a heating rate of 2-5℃ / min and held for 30-120 minutes, and finally cooled to room temperature with the furnace.

[0015] Beneficial effects (1) The plant laser illumination fluorescent microcrystalline glass provided by the present invention overcomes the overall instability of materials caused by the use of organic resins and other organic materials in conventional devices. It has good thermal stability, chemical stability and optical properties, and the preparation process is simple, low cost and suitable for industrial preparation and production. (2) The plant laser lighting fluorescent microcrystalline glass provided by the present invention, combined with a laser light source, can obtain a plant growth supplementary light source with highly matched spectrum. At the same time, it can also directly use the light conversion ability to convert the ultraviolet part of sunlight into visible light, which has potential application value in plant factories, greenhouses and other fields. (3) This invention utilizes the lattice reduction characteristics of microcrystals to reduce Eu without introducing a reducing agent or a reducing atmosphere. 3+ For Eu 2+ Blue fluorescence was obtained, and the crystalline phases were feldspar and diopside. This ensured both good fluorescence performance and the mechanical properties of the fluorescent material. Attached Figure Description

[0016] Figure 1 The emission spectra of the fluorescent microcrystalline glass obtained in Example 1 and Comparative Examples 1 and 3 are shown. Figure 2 The XRD patterns of the fluorescent microcrystalline glass obtained in Example 3 and Comparative Examples 1 and 2 are shown. Figure 3 The image shows the DSC pattern of the europium-doped silicate red fluorescent glass obtained in Example 3. Figure 4 The emission spectrum of the europium-doped silicate red and blue fluorescent microcrystalline glass obtained in Example 3 is shown. Detailed Implementation

[0017] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0018] First, the present invention provides a europium-doped silicate red-blue fluorescent microcrystalline glass. The chemical composition of the europium-doped silicate red-blue fluorescent microcrystalline glass may include: a glass matrix and a dopant, europium oxide (Eu₂O₃); preferably, the crystal phase of the europium-doped silicate red-blue fluorescent microcrystalline glass may include labradorite and diopside microcrystalline phases.

[0019] In some embodiments, the chemical composition of the glass matrix may include: 50-60 mol% SiO2, 10-20 mol% Al2O3, 0-10 mol% K2O, 0-10 mol% Na2O, 5-30 mol% CaO, 5-30 mol% MgO, and 0-10 mol% TiO2.

[0020] The content of CaO and MgO directly determines the type of crystals precipitated. If the content of CaO and MgO is not properly controlled, the final precipitated crystals will be quartz phase, which will weaken the luminescence ability of the final glass.

[0021] In some embodiments, the mass of the dopant europium oxide (Eu₂O₃) can be 1 to 10 wt% of the glass matrix.

[0022] In some embodiments, the crystallization mechanism of the glass matrix is ​​surface crystallization, and its main crystalline phases are labradorite ((Na,Ca)(Al,Si)4O8) and diopside (CaMgSi2O6).

[0023] In some embodiments, the europium-doped silicate red-blue fluorescent glass crystal is a mixed-valence europium ion-doped fluorescent glass crystal, which can simultaneously obtain fluorescence of divalent and trivalent europium ions when excited by ultraviolet light at 348 nm, 360 nm, and 393 nm. 2+ The center of the emission wavelength is 410nm, Eu 3+ The center of its emission wavelength is 612nm.

[0024] In some embodiments, the europium-doped silicate red and blue fluorescent glass-ceramics exhibit a thermal stability ΔT > 150°C, demonstrating good thermal stability and glass-forming properties. Here, thermal stability refers to the crystallization initiation temperature T of the glass-ceramics. c and glass transition temperature T g The difference between them.

[0025] In some embodiments, the activation energy E for crystallization of the europium-doped silicate red and blue fluorescent microcrystalline glass is... a <400KJ / mol, exhibiting good crystallization properties. The microcrystalline types are mainly labradorite and diopside, possessing good rare earth Eu content. 3+ The capacity and lattice sites of Eu 2+ Its self-repairing ability.

[0026] It should be noted that the labradorite ((Na,Ca)(Al,Si)4O8) and diopside (CaMgSi2O6) precipitated inside the microcrystalline glass provided by this invention offer an ideal local crystal environment for europium ions, further improving luminescence efficiency. Specifically, the low-symmetry crystal field environment provided by labradorite and diopside is beneficial for Eu ions. 3+ The increased radiative transition probability of these two crystals, along with their lower phonon energies (approximately 800-900 cm⁻¹ for labradorite and 850-950 cm⁻¹ for diopside), significantly reduces the likelihood of excited-state energy loss through multiphonon relaxation. The presence of diopside not only significantly enhances the luminescence intensity of the glass-ceramic but also optimizes the material's mechanical properties.

[0027] Unlike those containing only barium feldspar (BaA) l2 This invention relates to microcrystalline glass with crystalline phases such as Si2O8. Through precise compositional design (especially SiO2 50-60 mol%, CaO 5-30 mol%, MgO 5-30 mol%) and heat treatment processes, it achieves surface crystallization of both labradorite and diopside crystalline phases. The formation of the diopside crystalline phase as the second crystalline phase significantly improves the material's durability. The combined effect of the two crystalline phases not only enhances the Eu... 3+ Red light emission (mainly) 5 D0→ 7 F2 transition), while enhancing Eu 2+ The blue light emission of this invention gives the microcrystalline glass of the present invention a strong red-blue dual-color luminescence characteristic not found in conventional microcrystalline glass. In particular, the addition of diopside provides the glass with a more stable crystal structure, which not only helps to improve luminescence efficiency but also enhances the mechanical strength of the microcrystalline glass. By controlling the crystal field environment (low symmetry, low phonon energy) of labradorite and diopside and the microcrystalline strengthening mechanism, the microcrystalline glass of the present invention simultaneously achieves high luminescence efficiency and excellent mechanical properties.

[0028] Furthermore, Ca in the labradorite crystal phase 2+ Due to having a suitable radius (r) Eu2+ =131ppm, r Ca2+ =134ppm,r Ba2+ =161ppm), electricity price (+2 price) is one of the few that can promote Eu 3+ The self-reducing lattice type has enormous application potential. Furthermore, the blue light emission center of the labradorite crystal form is 410 nm, which, compared to other crystal forms (such as barium feldspar with an emission center of 373 nm), shows better matching with the blue light region (400-500 nm) of plant absorption spectra. In addition, this patent employs a composite microcrystal strategy, introducing a diopside crystal phase as a second microcrystal, further improving the mechanical properties of the glass-ceramic while enhancing luminescence intensity.

[0029] The following is an exemplary description of a method for preparing europium-doped silicate red and blue fluorescent microcrystalline glass provided by the present invention. The preparation method may include the following steps: (1) Weigh the raw material powder according to the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass and melt it to form a glass liquid; (2) The glass liquid is cast and annealed to obtain silicate red fluorescent glass; (3) The silicate red fluorescent glass is subjected to microcrystallization heat treatment to obtain europium-doped silicate red and blue fluorescent microcrystalline glass.

[0030] In some embodiments, in step (1), the raw material powder may include chemically pure SiO2, Al2O3, K2CO3, Na2CO3, CaCO3, MgO, TiO2, and Eu2O3.

[0031] In some embodiments, in step (1), the melting can be carried out in a platinum crucible at a temperature of 1500-1600°C for 2-4 hours.

[0032] In some embodiments, in step (2), the casting process can be carried out in a stainless steel mold, the casting temperature can be 300-500℃, and the casting time can be 20s-1min.

[0033] In some embodiments, in step (2), the annealing temperature can be 500-700°C, and the holding time can be 4-8 hours. Annealing can eliminate the internal stress inside the glass.

[0034] In some embodiments, in step (2), the thickness of the silicate red fluorescent glass can be 0.3-2 mm.

[0035] In some embodiments, in step (3), the microcrystallization heat treatment process can be as follows: heating from room temperature to nucleation temperature of 700-750°C at a heating rate of 2-5°C / min (e.g., 2°C / min) and holding at that temperature for 30-120 minutes (e.g., 120 minutes), then heating to microcrystallization temperature of 800-1200°C at a heating rate of 2-5°C / min (e.g., 5°C / min) and holding at that temperature for 30-120 minutes, and finally cooling to room temperature with the furnace.

[0036] Inappropriate control of heating rate, microcrystallization temperature and holding time can easily lead to insufficient or excessive microcrystallization, ultimately affecting the optical and mechanical properties of the glass.

[0037] Preferably, when the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass is 57.78 mol% SiO2, 10.57 mol% Al2O3, 1.4 mol% K2O, 4.11 mol% Na2O, 9.36 mol% CaO, 14.96 mol% MgO, 1.82 mol% TiO2, and 10 wt% Eu2O3, the microcrystallization temperature is 900–1200 °C.

[0038] Preferably, when the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass is 57.78 mol% SiO2, 10.57 mol% Al2O3, 1.4 mol% K2O, 4.11 mol% Na2O, 9.36 mol% CaO, 14.96 mol% MgO, 1.82 mol% TiO2, and 5 wt% Eu2O3, the microcrystallization temperature is 900–1100 °C.

[0039] Preferably, when the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass is 57.78 mol% SiO2, 10.57 mol% Al2O3, 1.4 mol% K2O, 4.11 mol% Na2O, 9.36 mol% CaO, 14.96 mol% MgO, 1.82 mol% TiO2, and 2 wt% Eu2O3, the microcrystallization temperature is 1000–1100 °C.

[0040] The lattice substitution reduction method employed in this invention provides a convenient preparation approach. Simultaneously, the microcrystalline glass system, with its unique glass-crystal composite structure, exhibits significant advantages in the field of rare-earth luminescent matrices: it achieves a synergistic enhancement of the low phonon advantage of the crystalline phase and the high optical transmittance and excellent mechanical properties of the glass phase through microcrystalization control, offering industrialization advantages such as simplified process flow, shortened production cycle, and controllable overall cost. It is particularly noteworthy that in the preparation method provided by this invention, Eu... 3+ For Ca 2+ The non-equivalent substitution allows the glass-ceramic to retain divalent europium in an air atmosphere, while the presence of calcium oxide and magnesium oxide confirms that the precipitated main crystalline phases are labradorite and diopside. Compared with the traditional atmosphere reduction method, this method has significant technical, economic, and environmental advantages.

[0041] This innovative technical solution utilizes europium-doped silicate microcrystalline glass, which, under ultraviolet excitation, produces a bimodal emission spectrum (410nm blue light and 612nm red light). The spectral matching degree is highly compatible with the effective radiation of plant photosynthesis, providing a high-efficiency fluorescence conversion material for intelligent supplemental lighting systems in facility agriculture. Furthermore, experimental results show that when this microcrystalline glass is excited with 348nm, 360nm, and 393nm ultraviolet light, both divalent and trivalent europium ions can be simultaneously emitted, with Eu...2+ The emission wavelength is 410nm, which opens up broad prospects for the application of microcrystalline glass in the field of plant growth lights.

[0042] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0043] Example 1

[0044] The method for preparing europium-doped silicate red and blue fluorescent microcrystalline glass provided in this embodiment includes the following steps: (1) According to the chemical composition of europium-doped silicate red and blue fluorescent microcrystalline glass (57.78 mol% SiO2, 14.96 mol% MgO, 10.57 mol% Al2O3, 9.36 mol% CaO, 1.4 mol% K2O, 1.82 mol% TiO2, 4.11 mol% Na2O, 5 wt% Eu2O3), the raw material powder (SiO2, Al2O3, K2CO3, Na2CO3, CaCO3, MgO, TiO2, Eu2O3 with a purity greater than 99%) was weighed and melted in an electric furnace (held at 1550℃ for 4 hours) to form a glass melt; (2) Pour the glass liquid into a stainless steel mold preheated to 400°C, and immediately place it into a muffle furnace at 650°C for annealing after the glass is formed to eliminate the internal stress inside the glass and obtain silicate red fluorescent glass. (3) Cut the silicate red fluorescent glass into 0.5 mm glass pieces and put them into a muffle furnace. Heat the glass to 700°C at a rate of 2°C / min and hold for 120 minutes. Then heat the glass to 1100°C at a rate of 2°C / min and hold for 120 minutes. Cool the glass to room temperature with the furnace to obtain the europium-doped silicate red and blue fluorescent microcrystalline glass.

[0045] Example 2

[0046] The preparation method of europium-doped silicate red and blue fluorescent microcrystalline glass provided in this embodiment is the same as that in Example 1, with the main difference being: In step (1), the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass is 55 mol% SiO2, 10 mol% Al2O3, 17.5 mol% MgO, 12.5 mol% CaO, 1 mol% K2O, 2 mol% TiO2, 2 mol% Na2O; 10 wt% Eu2O3; and the melting temperature is 1600℃. In step (2), the casting temperature is 500℃; In step (3), during the microcrystallization heat treatment, the heating rate of the microcrystallization temperature is 5℃ / minute, and the holding time is 30 minutes.

[0047] Example 3

[0048] The preparation method of europium-doped silicate red and blue fluorescent microcrystalline glass provided in this embodiment is the same as that in Example 1, with the main difference being: In step (1), the amount of Eu2O3 doping in the chemical composition of europium-doped silicate red and blue fluorescent microcrystalline glass is 10 wt% of the glass matrix; In step (3), the silicate red fluorescent glass is cut into 2mm glass sheets; the microcrystallization temperature is 900℃.

[0049] Example 4

[0050] The preparation method of europium-doped silicate red and blue fluorescent microcrystalline glass provided in this embodiment is the same as that in Example 1, with the main difference being: In step (1), the amount of Eu2O3 doping in the chemical composition of europium-doped silicate red and blue fluorescent microcrystalline glass is 10 wt% of the glass matrix; In step (3), the microcrystallization temperature is 900℃.

[0051] Comparative Example 1

[0052] The preparation method of the microcrystalline glass provided in this comparative example is the same as that in Example 1, with the main difference being: In step (1), the chemical composition of the glass matrix in the europium-doped silicate red and blue fluorescent microcrystalline glass includes 67.94 mol% SiO2, 12.43 mol% Al2O3, 1.65 mol% K2O, 4.83 mol% Na2O, 11.01 mol% CaO, and 2.14 mol% TiO2.

[0053] Comparative Example 2

[0054] The preparation method of the microcrystalline glass provided in this comparative example is the same as that in Example 1, with the main difference being: In step (1), the chemical composition of the glass matrix in the europium-doped silicate red and blue fluorescent microcrystalline glass includes 72.65 mol% SiO2, 13.29 mol% Al2O3, 11.77 mol% CaO, and 2.29 mol% TiO2.

[0055] Comparative Example 3

[0056] The preparation method of the microcrystalline glass provided in this comparative example is the same as that in Example 1, with the main difference being: In step (1), the amount of Eu2O3 doping in the chemical composition of europium-doped silicate red and blue fluorescent microcrystalline glass is 0.1 wt% of the glass matrix.

[0057] Figure 1 The emission spectra of the fluorescent glass-ceramics obtained in Example 1 and Comparative Examples 1 and 3 are shown in the figures. It can be seen from the figures that the crystalline phase of the glass-ceramic obtained in Comparative Example 1 does not contain the diopside phase, resulting in a decrease in its fluorescence intensity; the dopant content of the glass-ceramic obtained in Comparative Example 3 is too low, resulting in low luminescence intensity.

[0058] Figure 2 The XRD patterns are of the fluorescent glass-ceramics obtained in Example 3 and Comparative Examples 1 and 2. As can be seen from the figures, the main crystalline phases of the glass-ceramics obtained in Example 3 are labradorite ((Na,Ca)(Al,Si)4O8) and diopside (CaMgSi2O6, corresponding to JCPDS card number #00-017-0318); the main crystalline phases of the glass-ceramics in the comparative examples are labradorite ((Na,Ca)(Al,Si)4O8) and quartz (SiO2, corresponding to JCPDS card number #04-007-2518).

[0059] Figure 3 The figures show the DSC curves of the europium-doped silicate red fluorescent glass obtained in Example 3, with heating rates ranging from 5 to 20 kJ / min. The figures show that the corresponding glass transition temperature Tg and crystallization initiation temperature Tc are 737.6 °C and 983.6 °C (at a heating rate of 10 K / min), respectively.

[0060] Figure 4 The image shows the emission spectrum of the europium-doped silicate red-blue fluorescent glass-ceramic obtained in Example 3. As can be seen from the image, when the excitation light is 393 nm, the fluorescent glass-ceramic exhibits significant luminescence in both the 400-500 nm and 575-650 nm ranges, precisely matching the absorption spectrum of plants.

[0061] Table 1 below compares the performance data of the fluorescent glass prepared in Example 3 before and after microcrystallization:

[0062] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A europium-doped silicate red and blue fluorescent microcrystalline glass, characterized in that, The chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass includes: a glass matrix and a dopant europium oxide (Eu₂O₃); preferably, the crystal phase of the europium-doped silicate red and blue fluorescent microcrystalline glass includes labradorite and diopside microcrystalline phases; The chemical composition of the glass matrix includes: 50-60 mol% SiO2, 10-20 mol% Al2O3, 0-10 mol% K2O, 0-10 mol% Na2O, 5-30 mol% CaO, 5-30 mol% MgO, and 0-10 mol% TiO2; the mass of the dopant europium oxide (Eu2O3) is 1-10 wt% of the glass matrix.

2. The europium-doped silicate red and blue fluorescent glass-ceramic according to claim 1, characterized in that, The crystallization mechanism of the glass matrix is ​​surface crystallization, and its main crystalline phases are labradorite (Na,Ca)(Al,Si)4O8 and diopside CaMgSi2O6.

3. The europium-doped silicate red and blue fluorescent glass-ceramic according to claim 1 or 2, characterized in that, The europium-doped silicate red and blue fluorescent microcrystalline glass is a mixed-valence europium ion-doped fluorescent microcrystalline glass, which simultaneously exhibits fluorescence from divalent and trivalent europium ions when excited by ultraviolet light at 348 nm, 360 nm, and 393 nm. 2+ The emission wavelength is 410nm, Eu 3+ The center of its emission wavelength is 612nm.

4. The europium-doped silicate red and blue fluorescent glass-ceramic according to any one of claims 1-3, characterized in that, The europium-doped silicate red and blue fluorescent microcrystalline glass begins to crystallize at temperature T. c and glass transition temperature T g The difference between them is ΔT > 150℃.

5. The europium-doped silicate red and blue fluorescent glass-ceramic according to any one of claims 1-4, characterized in that, The activation energy E for crystallization of the europium-doped silicate red and blue fluorescent microcrystalline glass is... a <400KJ / mol.

6. A method for preparing europium-doped silicate red and blue fluorescent microcrystalline glass according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) Weigh the raw material powder according to the chemical composition of the europium-doped silicate red and blue fluorescent microcrystalline glass and melt it to form a glass liquid; (2) The glass liquid is cast and annealed to obtain silicate red fluorescent glass; (3) The silicate red fluorescent glass is subjected to microcrystallization heat treatment to obtain europium-doped silicate red and blue fluorescent microcrystalline glass.

7. The preparation method according to claim 6, characterized in that, In step (1), the melting temperature is 1500-1600℃ and the melting time is 2-4 hours.

8. The preparation method according to claim 6 or 7, characterized in that, In step (2), the casting temperature is 300-500℃ and the casting time is 20s-1min.

9. The preparation method according to any one of claims 6-8, characterized in that, In step (2), the annealing temperature is 500-700℃ and the holding time is 4-8 hours.

10. The preparation method according to any one of claims 6-9, characterized in that, In step (3), the microcrystallization heat treatment process is as follows: the temperature is increased from room temperature to nucleation temperature of 700-750℃ at a heating rate of 2-5℃ / min and held for 30-120 minutes, then the temperature is increased to microcrystallization temperature of 800-1200℃ at a heating rate of 2-5℃ / min and held for 30-120 minutes, and finally cooled to room temperature with the furnace.

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