JP3268004B2 - Method for producing fine particle-dispersed glass for nonlinear optical material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fine-particle-dispersed glass for nonlinear optical materials, and more particularly to a method for producing glass in which metal oxide fine particles are dispersed and precipitated. The fine particle-dispersed glass of the present invention is used as a glass material having a large nonlinear optical effect used in the optical information field, such as an optical switch and an optical wavelength conversion element.

[0002]

2. Description of the Related Art Glass containing semiconductor microcrystals has optical bistability, has a light relaxation time on the order of ps (picosecond), and has a quantum size effect. , A non-linear optical material that can be used for a third harmonic generation element (THG) and the like. Conventionally, CdS _x Se _(1-x) microcrystals and Cd
Multicomponent glasses containing S microcrystals are known and are commercially available as filter glasses. The semiconductor-containing glass is manufactured by heating a glass material serving as a matrix and a semiconductor material to form a glass melt, and then rapidly cooling and reheating the glass melt.

However, the conventional glass containing semiconductor microcrystals produced by such a melting method has a low concentration of semiconductor microcrystals due to volatilization of a semiconductor raw material during preparation of a glass melt, and is useful as a nonlinear optical material. Hard to say. For this reason, in order to improve the content concentration of semiconductor microcrystals, a semiconductor using a new glass material manufacturing technique such as a sol-gel method, a CVD method, a sputtering method, a simultaneous vapor deposition method, a lithography method, and the use of porous glass. Various attempts have been made to produce glass containing microcrystals.

At the same time, attempts have been made to obtain various semiconductor microcrystal-containing silica glass or semiconductor microcrystal-containing multi-component glass in order to obtain semiconductor microcrystal-containing glass having various nonlinear optical characteristics and optical characteristics.

For example, JP-A-3-187952 discloses that CdS and CdS are added to a glass matrix by a sol-gel method.
A glass material in which microcrystals of a II-VI compound semiconductor containing a chalcogen element (S, Se, Te) such as dSe or a compound semiconductor such as CuCl are precipitated is described. However, in order to precipitate microcrystals of these compound semiconductors, a metal element which is a component of the compound semiconductor is dissolved in a sol solution corresponding to the composition of the glass matrix to gel, and then a gas containing a chalcogen element, for example, H ₂ S, H ₂ Se
Or by contacting with a chlorine-containing gas such as HCl, or by reacting with a chalcogen or Cl. For this reason, a highly toxic gas is used in the production, which requires labor and complicated equipment for production management, and it is difficult to control the reaction.It is also possible to stably contain a large amount of compound semiconductors, and to sharpen the particle size of microcrystals. Difficult to keep stable.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel method for producing a fine particle-dispersed glass for a nonlinear optical material, which can be produced with a simple and easy-to-control production method and with high safety.

[0007]

This and other objects are achieved by the present invention which is defined below as (1) to (4). (1) In or Sn having a band gap of ₂ to 5 eV in a glass matrix containing SiO ₂ as a main component.
When obtaining a fine particle-dispersed glass for a nonlinear optical material containing fine particles having an average particle diameter of 1 to 20 nm of an oxide or a metal oxide that is a composite oxide of In or Sn, a sol solution having a composition according to the glass matrix, The metal constituting the metal oxide is contained, and this is made into a wet gel,
A method for producing a fine particle-dispersed glass for a non-linear optical material, which is further made into a dry gel and then vitrified to obtain a fine particle-dispersed glass for a non-linear optical material. (2) In or Sn having a band gap of ₂ to 5 eV in a glass matrix containing SiO ₂ as a main component.
When obtaining a fine particle-dispersed glass for a nonlinear optical material containing fine particles having a mean particle size of 1 to 20 nm of a metal oxide which is an oxide of In or Sn, a sol solution having a composition corresponding to the glass matrix is gelled. Production of fine particle-dispersed glass for non-linear optical material to obtain a wet gel, to contain the metal constituting the metal oxide in the wet gel, to form a dry gel, and then to vitrify to obtain fine-particle dispersed glass for non-linear optical material Method. (3) In or Sn having a band gap of ₂ to 5 eV in a glass matrix containing SiO ₂ as a main component.
When obtaining a fine particle-dispersed glass for a nonlinear optical material containing fine particles having an average particle diameter of 1 to 20 nm of a metal oxide which is an oxide or a composite oxide of In or Sn, a dry gel is prepared from a sol solution having a composition corresponding to the glass matrix. A method for producing a fine particle-dispersed glass for a non-linear optical material, wherein the metal constituting the metal oxide is contained in the dry gel, and the glass is vitrified to obtain a fine-particle-dispersed glass for a non-linear optical material. (4) The method according to any one of the above (1) to (3), wherein the fine particles are contained in an amount of 0.1 to 15 mol%.

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

In the fine particle-dispersed glass of the present invention, as a result of the three-dimensional confinement of the metal oxide fine particles, the glass has a higher energy gap value than that of the metal oxide bulk material, and a quantum effect due to the exciton confinement effect appears. As a result,
A nonlinear optical material having optical bistability and optical relaxation time on the order of ps is realized, and can be applied to an optical switch or an optical wavelength conversion element such as THG.

[0014]

[Specific Configuration] Hereinafter, a specific configuration of the present invention will be described in detail.

The fine particle-dispersed glass of the present invention contains fine particles of metal oxide. The metal oxide used has a band gap of 2 to 5 eV in bulk.

As such a metal oxide, In, S
oxides of n, Sb, Zn, Ti, Ba, for example, In ₂ O
₃ , SnO ₂ , Sb ₂ O ₅ , or a complex oxide thereof (In ₂ O ₃ ) _1-x (SnO ₂ ) _x (0 <x ≦ 0.
1), (SnO ₂ ) _1-x (Sb ₂ O ₅ ) _X (0 <x ≦
0.1). Especially indium oxide I
n ₂ O ₃ or indium-tin composite oxide In ₂ O
₃ -SnO ₂ especially _{(In 2 O 3) 1-} x (SnO 2)
_x (0 <x ≦ 0.1) is preferable because of easy production.

The average particle size of such metal oxide fine particles is 1 to 20 nm, preferably 2 to 10 nm. The quantum size effect is realized with such an average particle size. The content of the metal oxide fine particles is 0.1 to 15 mol%, particularly 1 to 10 mol, when the contents of the oxide constituting the glass matrix described later and the content of the fine particle metal oxide are respectively calculated in molar amounts. %. If the content is too small, the usefulness as a nonlinear optical material is diminished. If the content is too large, cracks are generated and vitrification cannot be performed, or crystallization occurs and opacity occurs. The average particle size of the fine crystal particles can be determined from the X-ray diffraction spectrum according to Scherrer's formula.

The glass matrix of the fine particle-dispersed glass of the present invention has SiO ₂ as a main component and at least ZrO ₂ , TiO ₂ , Al ₂ O ₃ , GeO ₂ , Na
₂ O, K ₂ O, Li ₂ O, MgO, ZnO, CaO, P
_{bO, BaO, B 2 O 3} , P 2 O 5, SrO and La
It preferably contains at least one oxide selected from the group consisting of ₂ O ₃ . In such a case,
Sol later - when making the glass of the present invention by gel process, and of these, the SiO ₂ 85 to 100 mol%, and preferably contains in particular 90 to 100 mol%.

Such a fine particle-dispersed glass of the present invention comprises:
For example, it can be manufactured by various methods such as a method using a porous glass as described in JP-A-3-164726. However, it is manufactured by a sol-gel method in that the content concentration of the fine particles can be increased, the size of the fine particles can be easily controlled, and the obtained glass has a high degree of freedom in shape.

In order to produce the fine particle-dispersed glass of the present invention by the sol-gel method, the following method is preferably employed.

That is, a dry gel containing a soluble salt of a metal element as a raw material of the fine metal oxide is obtained, and the dry gel is vitrified to disperse and precipitate fine metal oxide crystals in a glass matrix. Alternatively, before forming a dry gel, a sol solution corresponding to the composition of the glass matrix is gelled to form a wet gel, and the wet gel contains a solution in which a metal element serving as a raw material of the fine particle metal oxide is dissolved, and then the dry gel is formed. The dry gel may be vitrified to disperse and precipitate metal oxide fine particle crystals. Furthermore, after the sol solution contains a solution in which a metal element as a raw material of the fine particle metal oxide is dissolved, these wet gel and dry gel may be formed and vitrified.

When the fine particle-dispersed glass of the present invention is produced by such a method, the dry gel containing a metal element as a raw material of the fine particle metal oxide is composed of a single metal of the metal element, a metal oxide, a metal halide, and an inorganic metal. Using acid salts (nitrates, phosphates, etc.), organic acid salts (acetates, oxalates, etc.), metal organic compounds (metal alkoxides, alkyl metal compounds, etc.), metal complexes (chelate compounds, etc.), etc., or It can be obtained by preparing an aqueous solution, an organic solvent solution or an inorganic solvent solution, mixing this with a sol solution corresponding to the composition of the glass matrix, gelling and drying. In this case, it is preferable to use a soluble compound of the metal, and since the sol-gel reaction uses an aqueous solvent, it is particularly preferable to use a water-soluble metal salt such as a halide, an inorganic acid salt, and an organic acid salt.

When the wet gel corresponding to the composition of the glass matrix contains a solution in which the metal element serving as the raw material of the fine particle metal oxide is dissolved, a method of adding the solution containing the metal element to the wet gel may be used. A method of immersing the gel in the above solution can be used.

The optimal composition of the sol solution to be used can be selected according to the use of the fine particle-dispersed glass and the required properties such as the reflectance, refractive index, thermal expansion coefficient and weather resistance.

That is, SiO ₂ , ZrO ₂ , TiO
₂ , Al ₂ O ₃ , GeO ₂ , Na ₂ O, K ₂ O, Li ₂
O, MgO, ZnO, CaO, PbO, BaO, B ₂ O
₃ , an alkoxide corresponding to P ₂ O ₅ , SrO and La ₂ O ₃ and / or a derivative thereof, for example, methyltriethoxysilane, 3-aminopropyltriethoxysilane, trifluoropropyltrimethoxysilane or the like as a raw material; A sol solution can be prepared by blending these raw materials according to the desired composition of the glass matrix. When adding the fine particle metal oxide raw material to the sol solution, the timing of addition may be before, during, or after hydrolysis of the alkoxide or its derivative.

The formation of a wet gel of a sol solution and the formation of a dry gel of a wet gel may be performed by a treatment in a usual sol-gel method. That is, the sol solution is first hydrolyzed to form a wet gel. The hydrolysis is performed by mixing the alkoxide or its derivative with water and stirring. Also, when using a combination of Si alkoxide and its derivative with another metal alkoxide and its derivative,
After hydrolyzing a Si alkoxide or its derivative having a low hydrolysis rate first, another metal alkoxide and / or its derivative may be added and mixed, followed by further hydrolysis.

As described above, the raw material for the fine metal oxide can be added before, during or after the hydrolysis of the alkoxide or its derivative, but the timing of addition depends on the nature of the raw material. You. It is not always necessary to add as a solution as long as it is dissolved in the sol solution before gelation and becomes homogeneous.

The amount of water used for the hydrolysis depends on the type of the alkoxide or its derivative as the main raw material, but is preferably at least twice the molar amount of the alkoxide or its derivative.
By using a larger amount of water, the hydrolysis time can be adjusted. Furthermore, the reaction time can be shortened by using an acid such as hydrochloric acid, nitric acid or acetic acid or a base such as NH ₄ OH, pyridine or piperazine as a catalyst during the hydrolysis. The amount of the catalyst may be about 1 × 10 ⁻³ to 1 times the molar amount of the alkoxide or its derivative.
Further, a stabilizer such as dimethylformamide may be added.

In the hydrolysis, the reaction time can be adjusted by heating from room temperature to about 100 ° C. However, if the temperature is too high, rapid evaporation of the solvent, water, alkoxide and the like will occur. In such a case, evaporation of the solvent and the like can be prevented by performing heating and reflux using a cooler. By performing such a hydrolysis treatment, a wet gel can be obtained.

When the raw material of the metal oxide fine particles is contained in the wet gel, it is preferable to add a solution containing the raw material to the wet gel or to immerse the raw material in the solution containing the raw material in the wet gel as described above.

The drying time for converting the wet gel into a dry gel depends on the size and shape of the wet gel, the amount of residual water, the drying temperature, etc., but is usually about 10 hours to 1 week. Thereafter, when the temperature is gradually raised to 150 ° C., a dry gel with less residual moisture is obtained.

Thereafter, the dry gel is vitrified. The metal oxide fine particles are grown or dispersed and deposited by the heat treatment at this time. The heat treatment is performed in air or an oxidizing atmosphere at 400
It is preferred to heat at ~ 1200 ° C. By this heat treatment, growth or dispersion precipitation of the particle crystals and vitrification of the dry gel occur, and a glass in which metal oxide fine particles are dispersed and precipitated can be obtained. Note that the heat treatment is preferably performed in an air atmosphere at 900 to 1100 ° C. for about 1 to 50 hours.

In this manner, the glass of the present invention can be obtained.
It can be formed into any shape such as a chip.

[0034]

EXAMPLES Hereinafter, the present invention will be described in more detail by showing specific examples of the present invention.

Example 1 An ethanol solution of SnCl ₂ .2H ₂ O was prepared in a propylene beaker. 11.68 ml of ethanol was weighed, and 0.0380 g and 0.0564 g of ethanol were respectively weighed.
, 0.0760 g and 0.1520 g of SnCl ₂
- was dissolved 2H ₂ O.

Next, while stirring this, In (NO
_{3) 2} · 3H ₂ O, and 7.80ml of dimethylformamide (DMF), 23.45ml of Si (OC ₂ H _{5) 4}
Was added. In (NO ₃ ) ₂ .3H ₂ O is SnC
Depending on the amount of l _2, respectively 0.660 g, of 0.99
0 g, 1.320 g and 2.640 g. These addition amounts are 92 mol I with respect to Si (OC ₂ H ₅ ) 4.
n ₂ O ₃ .8 mol SnO ₂ ) corresponds to 2, 3, 4 and 8 mol% of indium tin oxide (ITO), respectively.

While stirring was continued, 24.8 ml of H ₂ O and 0.5 ml of 14.5N aqueous nitric acid solution were added, and stirring was further continued at 70 ° C. for 1.5 hours to carry out a hydrolysis reaction.
About 10 ml of this solution was dispensed into a Teflon container and dried at 55 ° C. for 5 days to form a dry gel. After this, 9
It heat-processed at 00-1100 degreeC for 5 to 24 hours, and vitrified.

When the ITO composition and the content of the obtained glass sample were chemically analyzed, the composition was almost the same as the compounding ratio. In addition, X-ray diffraction (X
RD) and transmission electron microscope (TEM) observation.
Further, the absorption edge was measured.

Table 1 shows the band gap energy at the absorption edge of each sample. XRD is shown in FIG. FIG.
As shown in the XRD spectrum, In ₂ O ₃
4. peak of (222) at 30.5 ° of fine crystal of 5.
The (400) peak at 4 ° and the (44) at 50.9 °
The peak of 0) is observed. Therefore, 30.5 ° (2
22) Using the Scherrer equation from the half width of the peak of ITO,
The average particle size of the fine crystal particles was determined. The results are also shown in Table 1. Also, when the average particle diameter x obtained in this way was used, the relationship between 1 / x ² and the band gap energy Eg was plotted. The results are shown in FIG. From the results shown in FIG. 1, it can be seen that the quantum size effect has developed.

[0040]

[Table 1]

FIG. 3 shows that 3 mol% of ITO, 1000
4 shows a TEM image of a heat-treated sample at 5 ° C. for 5 hours. FIG. 3 shows that the ITO fine particle crystals are dispersed with good dispersibility in the glass matrix.

When each of these samples was irradiated with a laser beam of 1.06 μm, generation of the third harmonic was confirmed.

[0043]

According to the present invention, a fine particle-dispersed glass for a nonlinear optical material having a novel quantum size effect is realized. This can be safely manufactured with a simple manufacturing method with good composition accuracy and particle size accuracy.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between 1 / x ² (x is the average particle size) showing the quantum size effect of the fine particle-dispersed glass for a nonlinear optical material of the present invention and the band gap energy Eg.

FIG. 2 is a graph showing an XRD spectrum of the fine particle-dispersed glass for a nonlinear optical material of the present invention.

FIG. 3 is a TEM photograph of the fine particle-dispersed glass for a nonlinear optical material of the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-296026 (JP, A) JP-A-3-187951 (JP, A) JP-A-3-109236 (JP, A) 187952 (JP, A) JP-A-2-225342 (JP, A) JP-A-3-97639 (JP, A) JP-A-5-119362 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03C 1/00-14/00 JICST file (JOIS)

Claims (4)

(57) [Claims] An average particle diameter of an oxide of In or Sn having a band gap of ₂ to 5 eV or a metal oxide which is a composite oxide of In or Sn in a glass matrix containing SiO ₂ as a main component. When obtaining a fine particle dispersion glass for nonlinear optical material containing fine particles of 20 nm, the sol solution of the composition according to the glass matrix, the metal constituting the metal oxide is contained, this is a wet gel, and further a dry gel, Then, vitrification is performed to obtain fine particle-dispersed glass for nonlinear optical material. 2. An average particle size of an oxide of In or Sn or a metal oxide which is a composite oxide of In or Sn having a band gap of ₂ to 5 eV in a glass matrix containing SiO ₂ as a main component. In obtaining fine particle dispersion glass for nonlinear optical material including fine particles of 20 nm, a sol solution having a composition according to the glass matrix is gelled to form a wet gel, and the metal constituting the metal oxide is contained in the wet gel. A method for producing a fine particle-dispersed glass for a non-linear optical material, which is formed into a dry gel and then vitrified to obtain a fine-particle-dispersed glass for a non-linear optical material. 3. An average particle diameter of an oxide of In or Sn or a metal oxide which is a composite oxide of In or Sn having a band gap of ₂ to 5 eV in a glass matrix containing SiO ₂ as a main component. In obtaining fine particle dispersion glass for non-linear optical material containing fine particles of 20 nm, a dry gel is obtained from a sol solution having a composition according to the glass matrix, and the metal constituting the metal oxide is contained in the dry gel, and this is mixed with glass. A method for producing a fine particle-dispersed glass for a non-linear optical material, the method comprising: 4. The method according to claim 1, wherein the fine particles are contained in an amount of 0.1 to 15 mol%.