A germanate glass-ceramics precipitating Li3AlF6 nanocrystals and a preparation method thereof

Abstract

The application discloses germanate glass ceramics precipitating Li3AlF6 nanocrystals and a preparation method thereof. The molar percentage of the glass ceramic components is as follows: 40-45% of GeO2, 10-15% of LiF, 10-15% of LuF3, 10-20% of Al2O3, 5-10% of YF3 and 10-15% of La2O3. The preparation method comprises the following steps: after high-purity raw materials of certain mass are weighed according to the above molar percentage and uniformly mixed, the raw materials are melted and kept for 15-45 minutes in an up-and-down furnace at 1400-1500 DEG C. Then, the glass melt is poured into a mold and placed in a muffle furnace, annealing and keeping for 3-5 hours at 400-500 DEG C, and then naturally cooled to room temperature, and the base glass is obtained. The prepared base glass is heat-treated at a crystallization temperature range thereof for 2-8 hours, and then naturally cooled to room temperature, so that the glass ceramic precipitating Li3AlF6 nanocrystals is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rare earth doped microcrystalline glass, in particular to a germanate microcrystalline glass containing Li3AlF6 nanocrystals and a preparation method thereof. BACKGROUND

[0002] With the rapid development of optoelectronic information technology, transparent optical material laser light source, display, luminescence, medicine and other fields represented by rare earth ion doped luminescent glass have been widely used. In order to obtain luminescent materials with excellent luminescent performance and good environmental adaptability, not only the substrate material for doping luminescence requires low phonon energy, but also it requires good thermal, chemical stability and mechanical properties.

[0003] Microcrystalline glass is a material between glass and crystal, which has the advantages of both. For fluorine-oxygen microcrystalline glass, fluoride nanocrystals with low phonon energy are uniformly distributed in the oxide glass network, and rare earth ions are preferentially enriched in fluoride crystal phase, which determines that fluorine oxide microcrystalline glass has the advantages of oxide glass and fluoride crystal. It has low phonon energy, high chemical stability and mechanical stability.

[0004] Because the size of the precipitated fluoride nanocrystals is generally tens of nanometers, which is much smaller than the wavelength of visible light, it has high transmittance to visible light. Therefore, in recent years, fluorine oxide microcrystalline glass has gradually attracted attention and research interest, and has potential application prospects in the fields of optical communication, three-dimensional display and solid-state lighting. SUMMARY

[0005] In order to solve the above technical problems existing in the prior art, the present application discloses a germanate microcrystalline glass precipitating Li3AlF6 nanocrystals and a preparation method thereof. Specifically, by designing the glass composition, a base glass is obtained by a melt quenching method, and then the base glass is heat treated to precipitate Li3AlF6 nanocrystals in the glass. The specific technical scheme is as follows:

[0006] A germanate microcrystalline glass precipitating Li3AlF6 nanocrystals, the glass has a molar percentage composition of:

[0007] Raw material Molar percentage (mol%)

[0008] GeO2 40~45%

[0009] LiF 10~15%

[0010] LuF310~15%

[0011] Al2O3 10~20%

[0012] YF3 5~10%

[0013] La2O3 10~15%。

[0014] A preparation method of the germanate glass-ceramics precipitating Li3AlF6 nanocrystals, comprising the following steps:

[0015] (1) batching: taking GeO2, LiF, LuF3, Al2O3, YF3 and La2O3 as the glass composition raw materials, and according to the selected molar percentage of the above glass composition, the corresponding mass of the raw materials is weighed and mixed uniformly in a mortar;

[0016] (2) melting: pouring the uniformly ground and mixed glass raw materials into a crucible, and placing it into a silicon-carbon rod electric furnace for melting, the melting temperature is 1400~1500℃, and the melting time is 25~30 minutes;

[0017] (3) forming: pouring the glass melt into a mold preheated to 400~500℃ for forming;

[0018] (4) annealing: placing the formed glass into a muffle furnace for annealing, the annealing temperature is 400~500℃, the annealing time is 3~5 hours, and then the power of the muffle furnace is turned off and the furnace is cooled to room temperature;

[0019] (5) heat treatment: performing heat treatment for several hours within the crystallization temperature range;

[0020] (6) polishing: cutting, grinding and polishing the glass after heat treatment to prepare the germanate glass-ceramics precipitating Li3AlF6 nanocrystals.

[0021] Further, the crystallization temperature in step (5) is 650~750℃.

[0022] Further, the melting temperature in step (2) is 1450℃, and the melting time is preferably 30 minutes.

[0023] Further, the preheating temperature in step (3) is 450℃.

[0024] Further, the annealing temperature in step (4) is 450℃, and the annealing time is 4 hours.

[0025] The germanate glass-ceramics precipitating Li3AlF6 nanocrystals of the present application can be used to prepare a volume Bragg grating (VBG) based on a photothermal sensitive (PTR) glass, and is applied to the optical field of laser system design, three-dimensional display and imaging, and optical communication. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments will be briefly introduced. Obviously, the accompanying drawings in the following description only need to be some embodiments of the present application.

[0027] Figure 1 XRD patterns of base glass and glass-ceramics in Example 1 DETAILED DESCRIPTION

[0028] The present application will be further described below in conjunction with the accompanying drawings. EMBODIMENT

[0029] According to the composition: 45GeO2-13LiF-12LuF3-15Al2O3-5YF3-10La2O3 (mol %), the required GeO2, LiF, LuF3, Al2O3, YF3, La2O3 powder raw materials with a total mass of 20 grams were weighed and put into an agate mortar for grinding and mixing uniformly. The uniformly mixed glass raw materials were poured into a crucible, covered with a mullite cover, and placed in a silicon-carbon rod electric furnace at 1450℃ for melting for 30 minutes. Then the glass melt was quickly poured into a preheated 500℃ mold, and after the glass was formed, it was transferred to a 450℃ muffle furnace for annealing for 5 hours. After natural cooling to room temperature, the base glass was obtained. The obtained base glass was heated to 700℃ at a heating rate of 10 ℃ / min and kept for 4h to obtain germanosilicate glass-ceramics containing Li3AlF6 nanocrystals. The obtained glass-ceramics were cut, ground and polished to make 10mm*10mm*1.5mm glass-ceramics. EMBODIMENT

[0030] According to the composition: 45GeO2-15LiF-10LuF3-10Al2O3-5YF3-15La2O3 (mol %), the required GeO2, KF, K2CO3, H3BO3, YF3, La2O3 powder raw materials with a total mass of 20 grams were weighed and put into an agate mortar for grinding and mixing uniformly. The uniformly mixed glass raw materials were poured into a crucible, covered with a mullite cover, and placed in a silicon-carbon rod electric furnace at 1500℃ for melting for 25 minutes. Then the glass melt was quickly poured into a preheated 400℃ mold, and after the glass was formed, it was transferred to a 500℃ muffle furnace for annealing for 3 hours. After natural cooling to room temperature, the base glass was obtained. The obtained base glass was heated to 710℃ at a heating rate of 10 ℃ / min and kept for 3h to obtain germanosilicate glass-ceramics containing Li3AlF6 nanocrystals. The obtained glass-ceramics were cut, ground and polished to make 10mm*10mm*1.5mm glass-ceramics. EMBODIMENT

[0031] According to the composition: 40GeO2-15LiF-13LuF3-15Al2O3-7YF3-10La2O3(mol %) weigh the required GeO2, LiF, LuF3, Al2O3, YF3, La2O3 powder raw materials with a total mass of 20 grams, put them into an agate mortar and mix them well. Pour the well-mixed glass raw materials into a crucible, cover it with a mullite cover, and place it in a silicon-carbon rod electric furnace at 1400°C for 30 minutes. Then quickly pour the glass melt into a preheated 450°C mold. After the glass is formed, transfer it to a 400°C muffle furnace for annealing for 4 hours. After natural cooling to room temperature, the base glass is obtained. The obtained base glass is heated to 690°C at a heating rate of 10°C / min and kept for 5h to obtain germanosilicate glass-ceramics containing Li3AlF6 nanocrystals. The obtained glass-ceramics is cut, ground and polished to make a 10mm*10mm*1.5mm glass-ceramics.

[0032] The above examples are used to explain and illustrate the present application, but not to limit the present application. Any modifications and changes made to the present application within the spirit and protection scope of the claims fall within the protection scope of the present application.

Claims

1. A germanate glass-ceramic which precipitates Li3AlF6 nanocrystals, characterized in that, The glass has a molar percentage composition of: Raw material molar percentage (mol%) GeO240~45% LiF10~15% LuF310~15% Al2O310~20% YF35~10% La2O310~15%.

2. A method for preparing the germanate glass-ceramic releasing Li3AlF6 nanocrystals according to claim 1, characterized in that The method comprises the following steps: (1) batching: taking GeO2, LiF, LuF3, Al2O3, YF3 and La2O3 as the glass composition raw materials, and weighing the corresponding mass of the raw materials according to the selected molar percentage of the glass composition, and grinding and mixing uniformly in a mortar; (2) melting: pouring the ground and mixed uniformly glass raw materials into a crucible, and placing the crucible into a silicon-carbon rod electric furnace to melt, the melting temperature is 1400~1500℃, and the melting time is 25~30 minutes; (3) forming: pouring the glass melt into a mold preheated to 400~500℃ to form; (4) annealing: placing the formed glass into a muffle furnace to anneal, the annealing temperature is 400~500℃, the annealing time is 3~5 hours, and then the power of the muffle furnace is turned off and the furnace is cooled to room temperature; (5) heat treatment: performing heat treatment at a crystallization temperature range for several hours; (6) polishing: cutting, grinding and polishing the glass after heat treatment to obtain germanate glass-ceramics in which Li3AlF6 nanocrystals are precipitated.

3. The method of claim 2, wherein the step of preparing the mixture is characterized by: The crystallization temperature in step (5) is 650~750℃.

4. The method of claim 2, wherein: The melting temperature in step (2) is 1450℃, and the melting time is preferably 30 minutes.

5. The preparation method according to claim 2, characterized in that: The preheating temperature in step (3) is 450℃.

6. The method of claim 2, wherein: The annealing temperature in step (4) is 450℃, and the annealing time is 4 hours.

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