Germanate glass-ceramics precipitating KF nanocrystals and preparation method thereof

Abstract

The application discloses germanate glass ceramics precipitating KF nanocrystals and a preparation method thereof. The molar percentage of the components of the glass ceramics is as follows: 40-50% of GeO2, 10-15% of KF, 5-10% of K2CO3, 10-20% of H3BO3, 5-10% of YF3 and 10-15% of La2O3. The preparation method comprises the following steps: after a certain amount of high-purity raw materials are weighed according to the above molar percentage, the raw materials are uniformly mixed, are melted in an up-and-down furnace at 1500-1600 DEG C and are kept for 30-60 minutes. Then, the glass melt is poured into a mold and is placed in an annealing furnace, is annealed and kept for 3-5 hours at a temperature below the glass transition temperature, is naturally cooled to room temperature, is taken out and the base glass is obtained. The prepared base glass is heat-treated at a crystallization temperature range of the base glass for 2-8 hours, is naturally cooled to room temperature and the germanate glass ceramics precipitating KF nanocrystals is obtained.

Description

Technical Field

[0001] The present invention relates to the field of rare earth doped glass-ceramics, and in particular to a germanate glass-ceramic containing KF nanocrystals and a preparation method thereof. Background Art

[0002] With the rapid development of optoelectronic information technology, transparent optical materials, represented by rare earth ion-doped luminescent glass, have been widely used in laser light sources, displays, luminescence, medicine, and other fields. To obtain luminescent materials with excellent luminescence properties and good environmental adaptability, the matrix material used for doping and luminescence must not only have low phonon energy but also possess good thermal, chemical, and mechanical properties.

[0003] Glass-ceramics are a material between glass and crystal, combining the advantages of both. In oxyfluoride glass-ceramics, low-phonon-energy fluoride nanocrystals are evenly distributed within the oxide glass network, while rare earth ions preferentially accumulate within the fluoride crystalline phase. This gives oxyfluoride glass-ceramics the advantages of both oxide glass and fluoride crystals: low phonon energy combined with high chemical and mechanical stability.

[0004] Because the precipitated fluoride nanocrystals are typically tens of nanometers in size, much smaller than the wavelength of visible light, they have a high transmittance for visible light. Consequently, oxyfluoride glass-ceramics have attracted increasing attention and research interest in recent years, with potential applications in optical communications, three-dimensional displays, and solid-state lighting. Summary of the Invention

[0005] To address the aforementioned technical problems in the prior art, the present invention provides a germanate glass-ceramic that precipitates KF nanocrystals and a preparation method thereof. Specifically, the glass composition is designed, a base glass is obtained by melt-quenching, and the base glass is then heat-treated to precipitate KF nanocrystals in the glass. The specific technical solution is as follows:

[0006] A germanate glass-ceramic with precipitated KF nanocrystals, wherein the glass has a molar percentage composition of:

[0007] Raw material molar percentage (mol%)

[0008] GeO2 40~50%

[0009] KF 10~15%

[0010] K2CO3 10~15%

[0011] H3BO3 10~20%

[0012] YF3 5~10%

[0013] La2O3 10~15%.

[0014] A method for preparing the germanate glass-ceramics with precipitated KF nanocrystals comprises the following steps:

[0015] (1) Ingredients: GeO2, KF, K2CO3, H3BO3, YF3 and La2O3 are used as glass composition raw materials, and the corresponding mass of raw materials is weighed according to the molar percentage of the selected glass composition, and ground and mixed uniformly in a mortar;

[0016] (2) Melting: Pour the ground and mixed glass raw materials into a crucible and place it in a silicon carbon rod electric furnace for melting. The melting temperature is 1400-1600 degrees Celsius and the melting time is 30-60 minutes.

[0017] (3) Molding: Pour the molten glass into a mold preheated to 500-600 degrees Celsius for molding;

[0018] (4) Annealing: Place the formed glass in a muffle furnace for annealing at a temperature of 500-600 degrees Celsius for 3-5 hours. Then turn off the power of the muffle furnace and cool it to room temperature.

[0019] (5) Heat treatment: Heat treatment is performed within the crystallization temperature range for several hours;

[0020] (6) Polishing: The heat-treated glass is cut, ground, and polished to produce germanate glass-ceramics with KF nanocrystals precipitated.

[0021] Furthermore, the crystallization temperature in step (5) is 700-800 degrees.

[0022] Furthermore, in step (2), the melting temperature is 1550 degrees Celsius, and the melting time is preferably 45 minutes.

[0023] Furthermore, in step (4), the annealing temperature is 550 degrees Celsius and the annealing time is 4 hours.

[0024] The germanate glass-ceramics with precipitated KF nanocrystals of the present invention has excellent mechanical strength and thermal stability, and can be used to prepare volume Bragg gratings (VBGs) based on photothermorefractive (PTR) glass, and further applied to laser system design, three-dimensional display and imaging, and optical communication. The method can controllably precipitate KF nanocrystals in germanate glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention.

[0026] Figure 1 This is the XRD diagram of the base glass and the microcrystalline glass in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings. Example

[0028] According to the composition of 40 GeO₂-15 KF-10 K₂CO₃-15 H₃BO₃-5 YF₃-15 La₂O₃ (mol%), 20 grams of GeO₂, KF, K₂CO₃, H₃BO₃, YF₃, and La₂O₃ powders were weighed and thoroughly ground in an agate mortar. The resulting glass was poured into a crucible, covered with a mullite lid, and melted in a silicon-carbon electric furnace at 1500°C for 45 minutes. The molten glass was then rapidly poured into a mold preheated to 550°C. Once formed, the glass was annealed in a muffle furnace at 500°C for 4 hours and then cooled naturally to room temperature to obtain a base glass. The resulting base glass was then heated in a muffle furnace at a rate of 10°C / min to 720°C and held there for 5 hours to obtain germanosilicate glass-ceramics containing KF nanocrystals. The obtained glass-ceramics are cut, ground and polished to produce glass-ceramics of 10mm*10mm*1.5mm. Example

[0029] According to the composition of 45 GeO₂-12 KF-13 K₂CO₃-10 H₃BO₃-5 YF₃-15 La₂O₃ (mol%), 20 grams of GeO₂, KF, K₂CO₃, H₃BO₃, YF₃, and La₂O₃ powders were weighed and thoroughly ground in an agate mortar. The resulting glass was poured into a crucible, covered with a mullite lid, and melted in a silicon-carbon rod electric furnace at 1550°C for 30 minutes. The molten glass was then rapidly poured into a mold preheated at 600°C. Once formed, the glass was annealed in a muffle furnace at 550°C for 4 hours and then cooled naturally to room temperature to obtain a base glass. The resulting base glass was then heated in a muffle furnace at a rate of 10°C / min to 730°C and held at that temperature for 5 hours to obtain germanosilicate glass-ceramics containing KF nanocrystals. The obtained glass-ceramics are cut, ground and polished to produce glass-ceramics of 10mm*10mm*1.5mm. Example

[0030] According to the composition of 45 GeO₂-12 KF-10 K₂CO₃-15 H₃BO₃-6 YF₃-12 La₂O₃ (mol%), 20 grams of GeO₂, KF, K₂CO₃, H₃BO₃, YF₃, and La₂O₃ powders were weighed and thoroughly ground in an agate mortar. The resulting glass was poured into a crucible, covered with a mullite lid, and melted in a silicon-carbon electric furnace at 1480°C for 45 minutes. The molten glass was then rapidly poured into a mold preheated at 500°C. Once formed, the glass was annealed in a muffle furnace at 600°C for 4 hours and then cooled naturally to room temperature to obtain a base glass. The resulting base glass was then heated in a muffle furnace at a rate of 10°C / min to 720°C and held there for 5 hours to obtain germanosilicate glass-ceramics containing KF nanocrystals. The obtained glass-ceramics are cut, ground and polished to produce glass-ceramics of 10mm*10mm*1.5mm.

[0031] The above embodiments are used to illustrate the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A germanate glass-ceramic with precipitated KF nanocrystals, characterized in that: The molar percentage composition of the glass is: Raw material molar percentage (mol%) GeO2 40~50% KF 10~15% K2CO3 10~15% H3BO3 10~20% YF3 5~10% La2O3 10~15%.

2. A method for preparing germanate glass-ceramics with precipitated KF nanocrystals as claimed in claim 1, characterized in that The steps include: (1) Ingredients: GeO2, KF, K2CO3, H3BO3, YF3 and La2O3 are used as glass composition raw materials, and the corresponding mass of raw materials is weighed according to the molar percentage of the selected glass composition, and ground and mixed uniformly in a mortar; (2) Melting: Pour the ground and mixed glass raw materials into a crucible and place it in a silicon carbon rod electric furnace for melting. The melting temperature is 1400-1600 degrees Celsius and the melting time is 30-60 minutes. (3) Molding: Pour the molten glass into a mold preheated to 500-600 degrees Celsius for molding; (4) Annealing: Place the formed glass in a muffle furnace for annealing at a temperature of 500-600 degrees Celsius for 3-5 hours. Then turn off the power of the muffle furnace and cool it to room temperature. (5) Heat treatment: Heat treatment is performed within the crystallization temperature range for several hours; (6) Polishing: The heat-treated glass is cut, ground, and polished to produce germanate glass-ceramics with KF nanocrystals precipitated.

3. The preparation method according to claim 2, wherein: The crystallization temperature in step (5) is 700-800 degrees.

4. The preparation method according to claim 2, wherein: In step (2), the melting temperature is 1550 degrees Celsius and the melting time is 45 minutes.

5. The preparation method according to claim 2, wherein: In step (4), the annealing temperature is 550 degrees Celsius and the annealing time is 4 hours.

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