JPH05254884A - Fine particle-dispersed glass for nonlinear optical material and its production - Google Patents

Abstract

PURPOSE:To obtain the subject dispersion glass having excellent composition and precision of particle diameter by adding a given metal to a sol solution having a composition corresponding to glass matrix, wetting the solution, drying and vitrifying. CONSTITUTION:A metal constituting a metal oxide (e.g. In2O3, SnO2, Sb2O3 or ZnO) having 1-20nm average particle diameter and 2-5ev band gap is prepared. The metal is added to a sol solution having a composition corresponding to a glass matrix. Then the sol solution is made into a wet gel, further a dry gel and then vitrified. Or the metal is added to the wet gel or the dry gel instead of blending the sol solution with the metal and vitrified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fine particle-dispersed glass for non-linear optical materials, and more particularly to glass in which metal oxide fine particles are dispersed and deposited. The fine particle-dispersed glass of the present invention is used as a glass material having a large nonlinear optical effect used in the field of optical information, 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 of the ps (picosecond) order, and has a quantum size effect. , Has attracted attention as a non-linear optical material that can be used for third harmonic generation elements (THG) and the like. Conventionally, as such glass, CdS _x Se _(1-x) crystallites and Cd
A multi-component glass containing S crystallites is known and is commercially available as a filter glass. This semiconductor-containing glass is manufactured by heating a glass raw material to be a matrix and a semiconductor raw material to form a glass melt, and then rapidly cooling and reheating the glass melt.

However, the conventional semiconductor microcrystal-containing glass produced by such a melting method has a low concentration of semiconductor microcrystals because the semiconductor raw material volatilizes during the preparation of the glass melt, and is useful as a nonlinear optical material. It is hard to say. Therefore, for the purpose of improving 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 is used. Various attempts have been made to produce glass containing fine crystals.

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

For example, in Japanese Unexamined Patent Publication No. 3-187952, CdS and C are added to a glass matrix formed by a sol-gel method.
It describes a II-VI compound semiconductor containing a chalcogen element (S, Se, Te) such as dSe, or a glass material obtained by depositing fine crystals of a compound semiconductor such as CuCl. However, in order to precipitate fine crystals of these compound semiconductors, a metal element that is a component of the compound semiconductor is dissolved and gelated in a sol solution according to the composition of the glass matrix, and then a gas containing a chalcogen element, for example, H 2 ₂ S, H ₂ Se
Alternatively, it is brought into contact with a chlorine-containing gas such as HCl or reacted with a chalcogen-based gas or Cl. Therefore, since a highly toxic gas is used in manufacturing, labor and complicated equipment are required for manufacturing control, the reaction is difficult to control, a large amount of compound semiconductor is stably contained, and the grain size of the microcrystals is sharp and sharp. It is difficult to keep stable.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel fine particle-dispersed glass for a nonlinear optical material which can be manufactured with high safety by a simple and easy-to-control manufacturing method, and a manufacturing method thereof. is there.

[0007]

These objects are achieved by the present invention described in (1) to (5) below.

(1) 2-5 eV in glass matrix
Average particle size of metal oxide having band gap of 1 to 20
Fine particle-dispersed glass for nonlinear optical materials containing fine particles of nm.

(2) The fine particle-dispersed glass for nonlinear optical material according to the above (1), wherein the fine particles are contained in an amount of 0.1 to 15 mol%.

(3) A sol solution having a composition corresponding to the glass matrix is made to contain a metal constituting the metal oxide, which is used as a wet gel and further as a dry gel, and then vitrified to obtain the above (1) or (). 2) A method for producing fine particle-dispersed glass for nonlinear optical materials, which obtains fine particle-dispersed glass for nonlinear optical materials.

(4) A sol solution having a composition corresponding to the glass matrix is gelled to obtain a wet gel, the metal constituting the metal oxide is contained in the wet gel, and this is made into a dry gel and then vitrified. A method for producing a fine particle dispersed glass for a nonlinear optical material, which obtains the fine particle dispersed glass for a nonlinear optical material according to any one of (1) and (2) above.

(5) A dry gel is obtained from a sol solution having a composition corresponding to the glass matrix, and the metal constituting the metal oxide is contained in the dry gel and vitrified to obtain the above (1) or (2). 1. A method for producing fine particle-dispersed glass for nonlinear optical materials, comprising obtaining the fine particle-dispersed glass for nonlinear optical materials according to

[0013]

In the fine particle-dispersed glass of the present invention, the fine particles of the metal oxide are confined three-dimensionally, and as a result, the energy gap value is higher than that of the bulk body of the metal oxide, and the quantum effect due to the exciton confinement effect appears. As a result,
A non-linear optical material having optical bistability and ps-order optical relaxation time is realized and can be applied to optical wavelength conversion elements such as optical switches and THGs.

[0014]

[Specific Structure] The specific structure of the present invention will be described in detail below.

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

Examples of such metal oxides include In and S
An oxide of n, Sb, Zn, Ti, Ba, such as In ₂ O
₃ , SnO ₂ , Sb ₂ O ₅ , ZnO, TiO _2, etc., or their composite oxide (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), BaTiO _{3 and the} like can be mentioned. Among these, iridium oxide In ₂ O ₃ or indium-tin composite oxide In ₂ is particularly preferable.
O ₃ -SnO ₂ especially _{(In 2 O 3) 1-} x (SnO
₂ ) _x (0 <x ≦ 0.1) is preferable because it is easy to manufacture.

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 below and the fine metal oxide particles are calculated in molar amounts. % Is preferable. If the content is too low, the usefulness as a nonlinear optical material is weakened, and if the content is too high, cracks may occur and vitrification may not be possible, or crystallization may occur to make the material opaque. The average particle diameter of the fine particle crystals can be obtained from the X-ray diffraction spectrum according to Scherrer's formula.

The glass matrix of the fine particle-dispersed glass of the present invention is not particularly limited, but SiO ₂ as a main component and at least ZrO ₂ , TiO ₂ as a minor component,
Al ₂ O ₃ , GeO ₂ , Na ₂ O, K ₂ O, Li ₂ O,
MgO, ZnO, CaO, PbO, BaO, B ₂ O ₃ ,
It preferably contains at least one oxide selected from the group consisting of P ₂ O ₅ , SrO and La ₂ O ₃ . In this case, the ratio of each component is arbitrary. In such a case, when the glass of the present invention is produced by the sol-gel method described below, among these, SiO ₂
It is preferable that the content is 5 to 100 mol%, particularly 90 to 100 mol%.

The fine particle-dispersed glass of the present invention as described above is
For example, it can be manufactured by various methods such as a method using porous glass as described in JP-A-3-164726. However, it is preferable to manufacture by the sol-gel method because 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 the shape.

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

That is, a dry gel containing a soluble salt of a metal element, which is a raw material for the fine particle metal oxide, is obtained, and this dry gel is vitrified to disperse and precipitate fine particles of the metal oxide 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 as a raw material of the fine particle metal oxide is dissolved, and then the dry gel Then, the dry gel may be vitrified to disperse and precipitate the metal oxide fine particle crystals. Further, the sol solution may be mixed with a solution in which a metal element, which is a raw material of the fine particle metal oxide, is dissolved, and then the wet gel and the dry gel may be prepared and vitrified.

When the fine particle-dispersed glass of the present invention is produced by such a method, the dry gel containing the metal element which is a raw material for the fine particle metal oxide is a simple substance of this metal element, a metal oxide, a metal halide or an inorganic material. Acid salt (nitrate, phosphate, etc.), organic acid salt (acetate, oxalate, etc.), metal organic compound (metal alkoxide, alkyl metal compound, etc.), metal complex (chelate compound, etc.), etc. It can be obtained by preparing an aqueous solution, an organic solvent solution or an inorganic solvent solution, and mixing this with a sol solution corresponding to the composition of the glass matrix, followed by gelation and drying. In this case, a soluble compound of a metal is preferably used, and since an aqueous solvent is used for the sol-gel reaction, it is particularly preferable to use a water-soluble metal salt such as a halide, an inorganic acid salt or an organic acid salt.

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

The composition of the sol solution to be used can be selected as an optimum composition depending on the use of the fine particle dispersed glass and the required characteristics such as 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 , P ₂ O ₅ , SrO and alkoxides corresponding to La ₂ O ₃ and / or its derivatives, for example, methyltriethoxysilane, 3-aminopropritriethoxysilane, trifluoropropyltrimethoxysilane, etc. as raw materials, A sol solution can be prepared by blending these raw materials according to the intended composition of the glass matrix. When the particulate metal oxide raw material is added to this sol solution, the addition time may be before, during, or after the hydrolysis of the alkoxide or its derivative.

The wet gelation of the sol solution and the dry gelation of the wet gel may be carried out by the usual treatment in the sol-gel method. That is, first, the sol solution is hydrolyzed to form a wet gel. The hydrolysis is performed by mixing alkoxide or its derivative with water and stirring. Further, when the Si alkoxide or its derivative is used in combination with another metal alkoxide or its derivative,
It is also possible to first hydrolyze the Si alkoxide or its derivative having a slow hydrolysis rate, then add another metal alkoxide and / or its derivative and mix them to further hydrolyze.

As mentioned above, the raw material of the particulate metal oxide can be added before, during, or after the hydrolysis of the alkoxide or its derivative, but the timing of addition is selected depending on the nature of the raw material. It Further, if the sol solution before gelation dissolves and becomes homogeneous, it is not always necessary to add it as a solution.

The amount of water used for hydrolysis depends on the kind of the alkoxide or its derivative as the main raw material, but is preferably twice or more the molar amount of the alkoxide or its derivative,
The hydrolysis time can also be adjusted by using a larger amount of water. Further, 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 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.

For 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 occurs. In that case, evaporation of the solvent and the like can be prevented by heating and refluxing using a cooler. A wet gel can be obtained by performing such a hydrolysis treatment.

When the wet gel contains the metal oxide fine particle raw material, it is preferable to add a solution containing the raw material to the wet gel or to immerse the wet gel in the solution containing the raw material, 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. Then, the temperature is gradually raised to 150 ° C., and a dry gel having less residual water is obtained.

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

In this way, the glass of the present invention can be obtained, which can be formed into a film structure on a substrate, a fiber,
It can be molded into an arbitrary shape such as a chip.

[0034]

EXAMPLES The present invention will be described in more detail below 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 out and 0.0380 g and 0.0564 g respectively
, 0.0760 g and 0.1520 g of SnCl ₂
・ 2H ₂ O was dissolved.

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}
And were added. _{In (NO 3) 2 · 3H} 2 O is, SnC
0.660 g and 0.99, respectively, depending on the amount of l ₂ added.
0 g, 1.320 g and 2.640 g. The addition amount of these is 92 mol I with respect to Si (OC ₂ H ₅ ) 4.
It corresponds to 2, 3, 4 and 8 mol% of indium tin oxide (ITO) of n ₂ O ₃ .8 mol SnO ₂ respectively.

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

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, the X-ray diffraction (X
RD) and a transmission electron microscope (TEM) observation.
Further, the absorption edge was measured.

The band gap energy at the absorption edge of each sample is shown in Table 1. The XRD is shown in FIG. Figure 2
As shown in, in XRD spectrum, an In ₂ O ₃
4. The (222) peak at 30.5 ° of the fine particle 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) ITO using the Scherrer's formula from the half width of the peak
The average particle size of the fine particle crystals was determined. The results are also shown in Table 1. Further, when the average particle diameter x thus obtained is set, the relationship between 1 / x ² and the band gap energy Eg was plotted. The results are shown in Figure 1. From the results shown in FIG. 1, it can be seen that the quantum size effect appears.

[0040]

[Table 1]

Further, in FIG. 3, ITO 3 mol%, 1000
A TEM image of a heat-treated sample at 5 ° C for 5 hours is shown. From FIG. 3, it can be seen that ITO fine particle crystals are dispersed in the glass matrix with good dispersibility.

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 product can be safely manufactured by a simple manufacturing method with good composition accuracy and particle size accuracy.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between 1 / x ² (x is an average particle size) showing a quantum size effect of a glass in which fine particles are dispersed for a nonlinear optical material of the present invention and bandgap energy Eg.

FIG. 2 is a graph showing an XRD spectrum of 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.

Claims (5)

[Claims] 1. A fine particle-dispersed glass for a nonlinear optical material, which comprises fine particles having an average particle diameter of 1 to 20 nm of a metal oxide having a band gap of 2 to 5 eV in a glass matrix. 2. The fine particle-dispersed glass for nonlinear optical material according to claim 1, wherein the fine particles are contained in an amount of 0.1 to 15 mol%. 3. A sol solution having a composition corresponding to the glass matrix is made to contain a metal constituting the metal oxide, which is used as a wet gel and further as a dry gel,
Next, a method for producing a fine particle-dispersed glass for a nonlinear optical material, which is vitrified to obtain the fine particle-dispersed glass for a nonlinear optical material according to claim 1. 4. A sol solution having a composition corresponding to the glass matrix is gelled to obtain a wet gel, the metal constituting the metal oxide is contained in the wet gel, and this is made into a dry gel and then vitrified. Item 1. A method for producing a fine particle-dispersed glass for a nonlinear optical material, which is capable of obtaining the fine particle-dispersed glass for a nonlinear optical material according to item 1 or 2. 5. A dry gel is obtained from a sol solution having a composition corresponding to the glass matrix, and the dry gel is made to contain a metal constituting the metal oxide and vitrified to obtain a dry gel. A method for producing a fine particle-dispersed glass for a nonlinear optical material for obtaining a fine particle-dispersed glass for a nonlinear optical material.