KR20220104528A - YAG synthesis method using PVA polymer solution method - Google Patents

Abstract

The present invention relates to a YAG synthesis method using a PVA polymer solution method. More specifically, the YAG synthesis method using a PVA polymer solution method includes the steps of: preparing a first metal nitrate containing Y positive ions and a second metal nitrate containing Al positive ions; dissolving the first metal nitrate and the second metal nitrate in prepared distilled water to produce a metal nitrate aqueous solution; generating a mixed solution by adding a certain amount of PVA polymer solution to the metal nitrate aqueous solution; generating a YAG precursor by gelling the resulting mixed solution while stirring at a constant temperature; drying the gelled YAG precursor; calcining the dried and gelled YAG precursor to produce a YAG precursor powder in which reaction gas is removed and PVA polymer is degreased; and heating the YAG precursor powder at a constant temperature to synthesize YAG powder. The synthesized YAG powder is controlled in particle size and shape according to the molecular weight of the PVA polymer and the amount of PVA polymer solution added. Synthesis of YAG powder is possible easily at low temperature.

Description

YAG synthesis method using PVA polymer solution method

The present invention relates to a YAG (Yttrium Aluminum Garnet, Y ₃ Al ₅ O ₁₂ ) synthesis method using a PVA (Polyvinyl Achol) polymer solution method. More specifically, it has excellent plasma resistance and recently Y ₂ O ₃ (Yttrium) It relates to a method for synthesizing YAG that can be used as a chamber coating material in a semiconductor process as an alternative material for

As the 3D-NAND business is in full swing in the rapidly changing semiconductor market, the importance of the semiconductor equipment industry is increasing, and as major semiconductor manufacturing processes such as deposition and etching are carried out in a harsher process environment, the demand for related plasma-resistant material parts is increasing. have.

In particular, as ultra-fine line width progresses in the semiconductor manufacturing process in which the plasma process proceeds, not only physical etching of the inner wall of the chamber, but also the generation of contaminant particles by chemical etching and accelerating the chemical reaction of the material, contamination by etching of the inner wall of the semiconductor Various studies are being conducted to prevent particle ingress.

Currently, Y ₂ O ₃ is used by thermal spray coating as the most commonly used plasma-resistant material for the inner wall of the chamber, but high-purity yttria has disadvantages in that it is expensive and the coating process is not simple.

To replace this, research and development using Y ₂ O ₃ composite oxides that are cheaper than the existing Y ₂ O ₃ and have excellent plasma resistance are being actively conducted.

A representative Y ₂ O ₃ composite oxide is YAG (Yttrium Aluminum Garnet, Y ₃ Al ₅ O ₁₂ ), which is a compound having a cubic Garnet crystal structure and is widely used in a wide range of fields due to its excellent creep resistance, thermal stability, corrosion resistance and optical properties. is being used

In addition, due to its excellent plasma resistance, it is used as a chamber coating material in a semiconductor process as a substitute material for Y ₂ O ₃ .

On the other hand, conventional YAG is a compound of Yttria (Y ₂ O ₃ ) and Alumina (Al ₂ O ₃ ), which is relatively simple and has been manufactured by a solid-phase reaction method mainly used for the synthesis of YAG. reduction was limited.

In Yttria and Alumina, in addition to YAG, which is the final product, YAM (Y ₄ Al ₂ O ₉ , Yttrium Aluminum monoclicnic) and YAP (YAlO ₃ , Yttrium Aluminum Perovstite) having a hexagonal structure exist as impurity phases. It is not easy to get YAG crystals.

In particular, since it requires a high-temperature heat treatment of about 1,600~1,800℃ for synthesis and a milling process to obtain fine powder, it causes particle aggregation, the particle shape becomes non-uniform, and defects in the surface and lattice occur, resulting in optical and mechanical properties There was a problem to reduce the .

The YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention was devised to solve the above problems, and it is possible to easily synthesize YAG powder at a low temperature using the PVA polymer solution method, and YAG powder It aims to provide a method for synthesizing YAG that can reduce the particle size of the particle size to sub-micron and is porous while having a dense surface microstructure.

On the other hand, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention includes the steps of preparing a first metal nitrate containing a Y cation and a second metal nitrate containing an Al cation, dissolving the first metal nitrate and the second metal nitrate in distilled water prepared to produce a metal nitrate aqueous solution, adding a certain amount of PVA polymer solution to the metal nitrate aqueous solution to create a mixed solution, gelling the resulting mixed solution at a constant temperature while stirring to produce a YAG precursor, the gelled Drying the YAG precursor, calcining the dried and gelled YAG precursor to remove the reactive gas and degreased the PVA polymer to produce a YAG precursor powder, and heat-treating the YAG precursor powder at a constant temperature to synthesize YAG powder may include

The particle size and shape of the preferably synthesized YAG powder may be adjusted according to the molecular weight of the PVA polymer and the amount of the PVA polymer solution added.

Preferably, the first metal nitrate may be Y(NO ₃ ) ₃ .6H ₂ O, and the second metal nitrate may be Al(NO ₃ ) ₃ .9H ₂ O.

Preferably, 5 g of PVA powder per 95 cc of distilled water may be dissolved in the PVA polymer solution.

Preferably, in the step of gelling the resulting mixture while stirring at a constant temperature to produce a YAG precursor, the YAG precursor may be produced by gelling while stirring on a hot plate at 200°C.

Preferably, the drying of the gelled YAG precursor may be performed by maintaining the dryer temperature at 200° C. for 24 hours.

Preferably, the step of calcining the dried and gelled YAG precursor to remove the reactive gas and to produce a YAG precursor powder from which the PVA polymer is degreased is heated to 600° C. at a temperature increase rate of 5° C./min in an air atmosphere and maintained for 1 hour. can

Preferably, in the step of synthesizing the YAG powder by heat-treating the YAG precursor powder at a constant temperature, it may be heated to 1,000° C. at a temperature increase rate of 5° C./min in an air atmosphere after calcination, and then maintained for 1 hour.

Preferably, after the step of synthesizing the YAG powder by heat-treating the YAG precursor powder at a predetermined temperature, the method may further include pulverizing the aggregated particles of the synthesized YAG powder.

Preferably, in the step of pulverizing the aggregated particles of the synthesized YAG powder, ball milling at 150 rpm using a zirconia ball having a diameter of 5 mm and an isopropyl alcohol solvent may be used and then pulverized by passing through a 150 mesh sieve.

Preferably, after the step of pulverizing the aggregated particles of the synthesized YAG powder, the method may further include molding the YAG powder into a predetermined shape.

Preferably, in the step of molding the YAG powder into a predetermined shape, it may be uniaxially pressed at a pressure of 50 MPa to form a pellet having a diameter of 15 mm, and then cold isostatically pressed to 200 MPa.

Preferably, after molding the YAG powder into a predetermined shape, the method may further include sintering the molded YAG powder.

Preferably, in the step of sintering the molded YAG powder, it may be heated to 1,700° C. at a temperature increase rate of 3° C./min in an air atmosphere, maintained for 6 hours, and then cooled.

In the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention, YAG powder can be easily synthesized at a low temperature using the PVA polymer solution method. The particle size of the powder can be reduced to sub-micron, and there is an excellent effect of synthesizing porous YAG powder with a dense surface microstructure.

1 is an overall process diagram of a YAG synthesis method using a PVA polymer solution method according to an embodiment of the present invention.
2 is a graph showing the DTA/TG results of the precursor gel prepared by the PVA (Mw. 146,000 ~ 186,000) polymer solution method.
3 to 5 are images showing the XRD patterns of YAG powder synthesized according to the PVA addition amount and molecular weight.
6 and 7 are images showing the microstructure after milling the YAG powder synthesized according to an embodiment of the present invention for 12 hours.
8 and 9 are images showing the SEM microstructure of the surface of the sintered body sintered using YAG powder synthesized by varying the molecular weight and addition amount of PVA.
10 is an image showing the SEM microstructure of YAG powder without ball milling (a) and YAG powder after 20 hours (b) and 30 hours (c) ball milling.
11 is an image showing the SEM microstructure of the surface of a sintered body obtained by sintering YAG powder without ball milling (a) and YAG powder milled for 20 hours (b) and 30 hours (c) under the same conditions.
12 is an image showing the microstructure of the fracture surface of the sintered body of FIGS. 11 ( b ) and 11 ( c ) showing densification in FIG. 11 .

The terms used in the present invention have been selected as widely used general terms as possible, but in certain cases, there are also terms arbitrarily selected by the applicant. should be taken into account to understand its meaning.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

In this regard, first, FIG. 1 is an overall process diagram of a YAG synthesis method using a PVA polymer solution method according to an embodiment of the present invention.

1, the YAG (Yttrium Aluminum Garnet, Y ₃ Al ₅ O ₁₂ ) synthesis method using the PVA polymer solution method according to an embodiment of the present invention includes a first metal nitrate containing a Y cation and an Al cation. preparing a second metal nitrate (S100) and dissolving the first metal nitrate and the second metal nitrate in prepared distilled water to generate an aqueous metal nitrate solution (S200).

At this time, the first metal nitrate according to an embodiment of the present invention is Y(NO ₃ ) ₃ ·6H ₂ O, and the second metal nitrate is Al(NO ₃ ) ₃ ·9H ₂ O.

In addition, the step of generating the metal nitrate aqueous solution (S200) is a step (S200) of dissolving the first and second metal nitrates in distilled water prepared according to a quantitative ratio.

On the other hand, in the YAG synthesis method using the PVA (Polyvinyl Achol) polymer solution method according to an embodiment of the present invention, after the above-described step (S200), a predetermined amount of the PVA polymer solution is added to the aqueous metal nitrate solution to generate a mixed solution ( S300).

At this time, various PVA polymer solutions may be used as the PVA polymer solution, but in an embodiment of the present invention, 5 g of PVA powder per 95 cc of distilled water is dissolved in the PVA polymer solution, and through the addition of the PVA polymer solution It can lead to homogeneous dispersion of metal cations.

In addition, the PVA polymer uses a PVA polymer having various molecular weights to control the particle size and shape of the synthesized YAG powder, and more specifically, has a molecular weight of 9,000 ~ 10,000Mw (Molecular weight) or 146,000 ~ 186,000Mw. PVA polymer is used.

Meanwhile, in an embodiment of the present invention, the amount of the PVA polymer solution added to the aqueous metal nitrate solution is added in a ratio of 4:1 and 2:1 with respect to the total valence ratio of the metal cations.

In detail, the mixing ratio was determined as the valence ratio of the metal cation to the PVA monomer having one -(OH) functional group based on the metal cations (Y and Al), and in one embodiment, yttrium (Y) Since ions and aluminum (Al) ions show a difference in electrons three times that of PVA, when added in a molar ratio of 4:1, the actual ratio of PVA between yttrium and aluminum ions becomes 12:1, respectively, due to the difference in charge.

Therefore, in order to match the ratio of 4:1, 5wt% PVA solution was added so that the ratio of Al ³⁺ : PVA and Y ³⁺ : PVA was 4:3, respectively. The PVA solution is added so that the PVA to PVA ratio is 2:3.

On the other hand, the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention includes the step (S400) of generating a YAG precursor by gelling the resulting mixture while stirring at a constant temperature.

In this case, the step (S400) of generating the YAG precursor may be performed through various devices and methods, but in an embodiment of the present invention, gelation is performed while stirring on a hot plate at 200°C.

Meanwhile, the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention includes drying the gelled YAG precursor (S500).

In this case, the above-described drying step (S500) is performed by maintaining the temperature at 200° C. for 24 hours using various dryers.

Meanwhile, the present invention includes a step (S600) of calcining the dried and gelled YAG precursor after the above-described drying step to remove the reactive gas and produce a YAG precursor powder in which the PVA polymer is degreased.

At this time, the reaction gas is NO _X gas, and this step is maintained for 1 hour after heating to 600° C. at a temperature increase rate of 5° C./min in an air atmosphere. YAG powder can be synthesized.

On the other hand, the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention comprises the step (S700) of synthesizing the YAG powder by heat-treating the YAG precursor powder at a certain temperature, in which case the YAG powder is synthesized ( S700) after calcination, is maintained for 1 hour after heating to 1,000 ℃ in an air atmosphere at a temperature increase rate of 5 ℃ / min.

On the other hand, in the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention, the YAG precursor powder is heat-treated at a predetermined temperature to synthesize the YAG powder (S700), followed by the crushing of the aggregated particles of the synthesized YAG powder. include more

At this time, the agglomerated particle grinding step may be performed using various methods and devices, but in an embodiment of the present invention, after ball milling at 150 rpm using a zirconia ball having a diameter of 5 mm and an isopropyl alcohol solvent, a 150 mesh sieve is passed through and crushed.

On the other hand, the present invention may further include the step of molding the YAG powder into a certain shape after the pulverizing the aggregated particles of the synthesized YAG powder. After forming with a furnace, cold isostatic pressing is performed at 200 MPa.

In addition, the present invention further includes a step of sintering the molded YAG powder after the above-described forming of the YAG powder, and this step is heated to 1,700° C. at a temperature increase rate of 3° C./min in an air atmosphere for 6 hours. It is maintained for a while and then cooled.

Hereinafter, the characteristics of the AG powder synthesized according to an embodiment of the present invention will be described in detail.

First, in order to examine the thermal decomposition characteristics according to the temperature expressed during the calcination of the precursor, a thermal analyzer (TG-DTA, Labsys Evo TG-DTA, SETARAM, France) was used in an air atmosphere at a temperature increase rate of 10°C/min to 900°C. carried out.

At this time, using an X-ray diffraction apparatus (XRD, SmartLab, Rigaku, Japan) to investigate the crystallization behavior according to the change in the molecular weight of the polymer, using the Cu-Kα (λ-1.542Å) characteristic wavelength, 40 kV, 30 mA was analyzed under the scan speed condition of 4°/min speed, the density of the sintered body was measured by Archimedesm method, and the relative density was calculated from the theoretical density of YAG 4.56 g/cm ³ .

The microstructure was observed using a field emission scanning electron microscope (FE-SEM, JSM-7100F, Jeol, Japan) to observe the morphology of the prepared powder and sintered body. The microstructure was observed.

The powder and sintered compact were fixed with carbon tape on an aluminum holder and coated with Pt sputter to observe the microstructure.

In this regard, referring to FIG. 2, which is a graph showing the DTA/TG results of the precursor gel prepared by the PVA (Mw. 146,000 ~ 186,000) polymer solution method, the precursor gel at room temperature absorbs moisture under the influence of metal nitrate. As the temperature increased, the surface moisture was removed and the weight began to decrease slightly.

Thereafter, as the temperature rises, the weight loss continues. The cause of the rapid weight loss from 300°C seems to be the removal of NOx gas in the precursor and thermal decomposition of the polymer.

At this time, an endothermic reaction is accompanied, and the exothermic reaction observed thereafter is due to the oxidation reaction of the carbon remaining after thermal decomposition, and the weight loss continued up to about 500°C.

After that, no further weight loss was observed, and based on these results, the calcination temperature of the precursor was set at 600°C.

On the other hand, during the drying process of removing the solution in PVA solution synthesis, a phenomenon was observed in which the volume of the precursor was increased several times or more, and this phenomenon was slightly different depending on the molecular weight of the polymer and the amount added.

On the other hand, attached Figures 3 to 5 are images showing the XRD pattern of the YAG powder synthesized according to the PVA addition amount and molecular weight.

First, FIG. 3 shows the results obtained by heat-treating a precursor prepared using PVA having a relatively high molecular weight of 146,000 to 186,000 at 800° C. (a) and 1,000° C. (b).

In the powder synthesized at 1,000 ° C, only the YAG peak was observed, but at 800 ° C, a small amount of YAP (YAlO ₃ ) was observed as a side reaction material. .

In the case of synthesizing YAG powder by the conventional solid-phase reaction method, a synthesis temperature of at least 1,200°C is required, and at a temperature below that, a complete phase transition to YAG did not occur, and YAM and YAP, which are side reactants, were observed. When synthesizing the powder, a temperature of at least 1,100° C. and a heat treatment time of 5 hours were required.

Meanwhile, referring to FIG. 4, FIG. 4 is an XRD diffraction peak of a powder synthesized at 1000° C. by adding PVA having a molecular weight of 146,000 to 186,000 at an addition ratio of 2:1 (a) and 4:1 (b). No side-reacted substances were observed in any of the branches, only the pure YAG phase was observed, and when the addition amount was high (addition ratio of 2:1), the crystalline phase intensity of the peak showed a tendency to increase.

In addition, Figure 5 shows the XRD results of the synthesized powder with the PVA molecular weight ((a) Mw. , In both of the synthesized powders, side reaction materials were not observed and only the YAG crystal phase was observed, but when PVA having a high molecular weight was used, a more developed crystal phase peak could be confirmed.

From the above results, it was confirmed that YAG synthesis by the PVA polymer method has a large molecular weight of PVA, and smooth synthesis is expressed when the amount of PVA is increased and heat treatment at a temperature of 1000° C. or higher is performed.

Meanwhile, FIGS. 6 and 7 are images showing the microstructure of YAG powder synthesized according to an embodiment of the present invention after milling for 12 hours. The microstructure of one YAG powder is shown.

The YAG powder synthesized in the PVA 2:1 (a) ratio showed relatively little large agglomeration compared to the PVA 4:1 (b) ratio, and the YAG powder synthesized in the 2:1 ratio was about 3 μm. On the other hand, the 4:1 ratio was observed to have a size of about 5 μm, confirming that the size of the primary particles was smaller as the amount of PVA added increased.

As a result, as the amount of PVA added decreased, the particle size of the synthesized YAG powder increased, and the shape showed an angular shape.

Meanwhile, FIG. 7 shows the microstructure of YAG powder synthesized in different amounts using PVA having a high molecular weight of 146,000 to 186,000.

The powder synthesized in the PVA 2:1(a) ratio showed a particle size of about 2 μm, and the powder synthesized in the PVA 4:1(b) ratio was observed to have a particle size of about 3 μm, and high molecular weight PVA was used. The synthesized YAG powder showed a relatively smaller particle size after ball milling than the YAG powder synthesized using low molecular weight PVA.

In addition, in the case of YAG powder synthesized with PVA 2:1 addition amount, sub-micron size powder was observed in the particle size distribution result. , shows that it is pulverized into very fine particles through the pulverization process.

On the other hand, as a sintering aid, MgO, SiO ₂ is known to improve densification during YAG sintering to obtain a sintered body close to the theoretical density, and also promotes grain growth.

According to a previous study, it has been reported that a sintering density of about 99% was obtained at 1,650°C by adding a sintering aid such as MgO or TEOS, and a transparent YAG sintered body was prepared by vacuum sintering at 1,750°C for 20 hours.

On the other hand, the YAG synthesis method using the PVA polymer solution method according to an embodiment of the present invention is characterized in that the YAG powder is synthesized by the PVA polymer solution method and then densified without adding a sintering aid.

On the other hand, Table 1 shows the relative density of the sintered body prepared according to the molecular weight and addition amount of PVA, prepared using a powder pulverized for 12 hours, and sintered at 1,700° C. in an air atmosphere for 6 hours.

PVA content ratio PVA Mw. Relative density (%)
2:1 9,000 91.8 146,000 95.7
4:1 9,000 72.3 146,000 82.4

Referring to Table 1 above, the relative density of the sintered compact at 146,000 PVA molecular weight and 2:1 addition amount was 95.7%, indicating the highest value. It is judged that high density was exhibited under favorable sintering conditions.

Conversely, when a relatively small amount of PVA having a low molecular weight was mixed, the particles of the synthetic powder were angular and agglomerated severely (see FIG. 6(b)), which resulted in a low relative density of 72.3%.

On the other hand, Figure 8 (PVA molecular weight (Mw. 9,000 ~ 10,000) (a) is 2:1, (b) is 4:1) and 9 (PVA molecular weight (Mw. 146,000 ~ 186,000) (a) is 2:1, (b) 4:1) is an image showing the SEM microstructure of the surface of a sintered body sintered using YAG powder synthesized by varying the molecular weight and addition amount of PVA. When the amount of PVA added was large (2:1), a more dense microstructure was observed, and a grain size of 1-3 μm was observed.

On the other hand, in FIG. 9 , similar results are shown even when high molecular weight PVA is used, showing a relatively dense microstructure as if reflecting 95.7% relative density at a PVA addition amount of 2:1.

As for the size of the grains, grain growth was sufficiently expressed, and a grain size of 2-5 μm was observed.

On the other hand, the synthesized YAG powder is very soft and porous due to the PVA solution synthesis method, and the particle size and shape of the powder can be easily changed depending on the ball milling conditions.

In the case of YAG powder synthesized by adding high molecular weight PVA in a 2:1 ratio, the porosity of the powder was more pronounced, and the ball milling effect was larger (Fig. 7(a)).

Based on these results, in order to examine the effect of the powder prepared by varying the ball milling grinding time on the final sintered body, a comparative experiment was conducted using a powder without ball milling after synthesizing YAG powder and a powder with an increased ball milling time. .

On the other hand, Figure 10 is an image showing the SEM microstructure of YAG powder without ball milling (a) and 20 hours (b) and 30 hours (c) ball milling YAG powder, YAG powder without ball milling (a) Silver porous particles of about 100 μm in size were observed, and the ball milled YAG powder was observed to have a finer average particle diameter of about 1 μm than the YAG powder that was ball milled for 12 hours. there was.

In addition, it was found that ball milling for more than 20 hours had no significant effect on the grinding effect.

On the other hand, FIG. 11 is an image showing the SEM microstructure of the surface of a sintered body obtained by sintering YAG powder without ball milling (a) and YAG powder milled for 20 hours (b) and 30 hours (c) under the same conditions. In the case of the sintered compact using the untreated powder, a large number of large pores were observed, and the relative density showed a value of 80.3%.

This is considered to be the result of inhomogeneous agglomeration during molding due to large particles of inhomogeneous size.

On the other hand, it was confirmed that the sintered compact using the powder milled for 20 hours and 30 hours showed a dense microstructure compared to the result of ball milling for 12 hours (FIG. 9), and the relative densities showed values of 97.8% and 97.2%, respectively. .

On the other hand, FIG. 12 is an image showing the microstructure of the fracture surface of the sintered body of FIGS. 11 (b) and 11 (c) showing densification in FIG. 11 ((a) is 20 hours milling, (b) is 30 hours milling). In contrast to the surface of the sintered body, intragranular fractures along with pores were mainly observed inside the sintered body.

As a result, the YAG synthesis method using the PVA polymer solution method according to the embodiment of the present invention can easily synthesize YAG powder at a low temperature through the above-described technical configurations, and the molecular weight of the PVA polymer and the amount of the PVA polymer solution added Accordingly, the particle size of YAG powder can be reduced to sub-micron, and there is an excellent effect of synthesizing porous YAG powder with a dense surface microstructure.

As described above, the present invention has been illustrated and described with reference to preferred embodiments, but it is not limited to the above-described embodiments and is not limited to those of ordinary skill in the art to which the invention pertains without departing from the spirit of the present invention. Various changes and modifications will be possible.

Claims (13)

Preparing a first metal nitrate containing a Y cation and a second metal nitrate containing an Al cation;
dissolving the first metal nitrate and the second metal nitrate in distilled water to produce an aqueous metal nitrate solution;
adding a predetermined amount of a PVA polymer solution to the aqueous metal nitrate solution to create a mixed solution;
generating a YAG precursor by gelling the resulting mixture while stirring at a constant temperature;
drying the gelled YAG precursor;
calcining the dried and gelled YAG precursor to produce a YAG precursor powder in which the reaction gas is removed and the PVA polymer is degreased; and
Comprising the step of synthesizing the YAG powder by heat-treating the YAG precursor powder at a certain temperature, the synthesized YAG powder is characterized in that the particle size and shape are controlled according to the molecular weight of the PVA polymer and the amount of the PVA polymer solution added. YAG synthesis method using PVA polymer solution method.
The method of claim 1,
The first metal nitrate is Y(NO ₃ ) ₃ ·6H ₂ O, and the second metal nitrate is Al(NO ₃ ) ₃ ·9H ₂ O YAG synthesis method using a PVA polymer solution method, characterized in that.
3. The method of claim 1 or 2,
The PVA polymer solution is a YAG synthesis method using a PVA polymer solution method, characterized in that 5 g of PVA powder per 95 cc of distilled water is dissolved.
3. The method of claim 1 or 2,
YAG synthesis method using a PVA polymer solution method, characterized in that in the step of generating the YAG precursor by gelling the resulting mixture while stirring at a constant temperature, the YAG precursor is produced by gelling while stirring on a hot plate at 200°C.
3. The method of claim 1 or 2,
The drying of the gelled YAG precursor is a YAG synthesis method using a PVA polymer solution method, characterized in that it is performed by maintaining the dryer temperature at 200° C. for 24 hours.
3. The method of claim 1 or 2,
The step of calcining the dried and gelled YAG precursor to remove the reactive gas and to produce a YAG precursor powder from which the PVA polymer is degreased is heated to 600° C. at a temperature increase rate of 5° C./min in an air atmosphere and maintained for 1 hour. YAG synthesis method using the PVA polymer solution method.
3. The method of claim 1 or 2,
In the step of synthesizing the YAG powder by heat-treating the YAG precursor powder at a certain temperature, the PVA polymer solution method, characterized in that after calcining, heating to 1,000° C. YAG synthesis method using.
3. The method according to claim 1 or 2,
After synthesizing the YAG powder by heat-treating the YAG precursor powder at a predetermined temperature, the YAG synthesis method using the PVA polymer solution method, characterized in that it further comprises a step of pulverizing the aggregated particles of the synthesized YAG powder.
9. The method of claim 8,
YAG using a PVA polymer solution method, characterized in that the milling step of the agglomerated particles of the synthesized YAG powder is ball milled at 150 rpm using zirconia balls having a diameter of 5 mm and isopropyl alcohol solvent, and then passed through a 150 mesh sieve to be pulverized. synthesis method.
9. The method of claim 8,
YAG synthesis method using a PVA polymer solution method, characterized in that it further comprises the step of molding the YAG powder into a predetermined shape after the pulverizing the aggregated particles of the synthesized YAG powder.
11. The method of claim 10,
The step of molding the YAG powder into a certain shape is a YAG synthesis method using a PVA polymer solution method, characterized in that it is uniaxially pressed at a pressure of 50 MPa to form a pellet having a diameter of 15 mm, and then cold isostatically pressed at 200 MPa.
11. The method of claim 10,
YAG synthesis method using a PVA polymer solution method, further comprising the step of sintering the molded YAG powder after the step of molding the YAG powder into a predetermined shape.
13. The method of claim 12,
The sintering of the molded YAG powder is a YAG synthesis method using a PVA polymer solution method, characterized in that after heating to 1,700° C. at a temperature increase rate of 3° C./min in an air atmosphere, maintaining for 6 hours, and then cooling.

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