JPS62256726A - Production of sr-zr-ti-o base dielectric power - Google Patents

Abstract

PURPOSE:To produce Sr-Zr-Ti-O dielectric power having easy sinterability and uniform compsn. by adding a zirconium anhydride soln. to an alcohol soln. contg. the alkoxide of Sr and inorg. titanium salt, etc., to hydrolyze the same. CONSTITUTION:Metallic Sr is dissolved in an alcohol soln. at 40 deg.C-the b.p. of alcohol in an inert gaseous atmosphere to form the alkoxide of the Sr. On the other hand, an inorg. zirconium salt is dissolved in a water-alcohol soln. mixture contg. water of 1-50 times mol of the above-mentioned Sr and the alcohol of the amt. larger than the same at the above-mentioned temp. A titanium tetraalkoxide or inorg. titanium salt is then dissolved in the above- mentioned alcohol soln. or water-alcohol soln. mixture. Said water-alcohol soln. mixture is added to said alcohol soln. to hydrolyze the alcohol soln. in the above-mentioned atmosphere and temp. The precipitate obtd. by the coprecipitation is separated and is subjected to a heating treatment at 400-1,000 deg.C after drying, by which the precipitate is pulverized. The Sr-Zr-Ti-O base dielectric power is thus stably obtd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to dielectric ceramic materials that are dense and have few defects, such as dielectric resonators and duplexers for microwave communication equipment, or substrates for microstrip circuits. Sr to obtain
-Zr-Ti-0-based dielectric powder manufacturing method.

[Conventional technology]

Composition formula Sr Zr +-! The porcelain material represented by TiXO3 (0≦X≦1) has been widely known as a dielectric material used in capacitors, etc., and is particularly known as a dielectric material with a high dielectric constant and a small temperature change in dielectric constant ( °≦X≦0
A range of porcelain materials are known as dielectrics for microwave communications. For example, Journal of the American Ceramic Society, Vol. 7, p. 56, pp. 352-354;
'High permissionTempera
ture-5table Ceramic Diele
ctrics with Low Microwave
According to Loss @ (R Sequel, General Electric Company Central Research Laboratory), the composition at which the temperature coefficient of dielectric constant becomes 0 is 0.043 < x < for the average from -50 to +100'O at 1.6 KHz. 0.048 for averages from 0 to 60"C at 4GHz.
, o6o<x<o, o6a. Also, SrZ
ro, +++5Tio-, 1.6KHz of 4sOs,
The relative dielectric power at 4 GHz is 34.2.8, respectively.
It is 3.9.

In addition, as a method for producing the raw material powder of the above-mentioned Sr-Zr-Ti-0 type dielectric ceramic material, a dry method using a solid phase reaction is generally used, and the raw material obtained by ball-milling after the solid phase reaction is used. The particle size of the powder was approximately 1-05 μm at most.

On the other hand, recently, raw material powders obtained by wet chemical means have been found to be effective in terms of sinterability and properties. The composition is uniform,
By using high-purity fine powder as a raw material, a dense dielectric magnetism can be obtained, and these BaTiO3
For the synthesis of 8rTiO,
4. It is known from various documents including Japanese Patent Publication No. 59-39725. Furthermore, it is known from Japanese Patent Publication No. 111921/1983 that a fine powder of BaZrO3 can be obtained by reacting an inorganic metal salt in a strong alkaline aqueous solution.

By the way, such SrZr1-xTIx03 (0≦X≦
The dielectric fine powder represented by the composition formula of
, -δZr1-xTix05-δ, it has the property that the sinterability of the fine powder deteriorates significantly as the value of δ approaches 0 from a positive value.

In addition, the inventors have discovered that unless the value of δ is sufficiently close to 0, the resulting sintered body, that is, the dielectric ceramic material, has a property that the microwave loss is large. The inventors have discovered through experiments using a dry method that a porcelain material whose temperature is sufficiently close to O cannot produce a dense sintered body even if fired at a temperature of 1600°C. Conventionally, for this reason, sintering properties have been improved by adding a sintering aid, but as the amount of the sintering aid added increases, the loss increases, and no benefits are obtained.

Furthermore, when looking microscopically at the dielectric porcelain obtained by sintering the fine powder obtained by the conventional dry method described above, it is found that the composition is non-uniform and the porosity is relatively high due to the large particle size. Due to this, properties such as dielectric constant and microwave loss may vary, and these properties may not be fully exhibited.

On the other hand, in the wet method of obtaining fine powder with a uniform composition, the method of using only metal alkoxide as a starting material has the disadvantage that metal alkoxide is expensive, difficult to receive a stable supply, has high manufacturing costs, and is not suitable for practical use. In the method of coprecipitating only inorganic metal salts, the pH of the solution must be set to 18 or higher in order to precipitate the Sr component. It is unavoidable that hot water ions such as Na and Na are mixed in as impurities, and if such a highly concentrated precipitant is used, the precipitate will significantly aggregate and gel.

[Problem that the invention seeks to solve]

As mentioned above, in the case of the dry method, if an attempt is made to reduce the loss of microwaves, the sinterability deteriorates. Adding a sintering aid to improve sinterability increases microwave loss. Furthermore, there were other problems such as the characteristics being easily fluctuated.

On the other hand, the wet method has problems such as contamination of impurities and gelation.

This invention was made to solve the above-mentioned problems, and it is possible to create a dense sintered body with less loss in the microwave high frequency band and less variation in composition by sintering at 1600'0 or less. The object of the present invention is to provide a manufacturing method that can stably supply Sr-Zr-'r2-o dielectric powder that is easily sinterable and has a uniform composition.

[Means for solving problems]

The method for producing the Sr-Zr-Ti-Q dielectric powder of the present invention is as follows: Metal strontium is heated at 40% by weight in an inert gas atmosphere.
A first dissolution step of forming an alkoxide of strontium by dissolving it in the alcohol solution at a temperature range of 1 to 50 times the number of moles of the metal strontium in the above temperature range, and A second dissolution step of dissolving titanium tetraalkoxide or inorganic titanium salt in the alcohol solution or titanium tetraalkoxide in inorganic zirconium salt on the water plate. or the inorganic titanium salt is dissolved in the water-alcohol solution in the above temperature range, and after the first to third dissolution steps, the above alcohol is dissolved in the water-alcohol solution in the above temperature range in an inert gas atmosphere. Step 1 of adding the above-mentioned water-alcohol mixed solution to the -/l/solution, hydrolyzing the above-mentioned alcohol solution, and co-precipitating, and separating the obtained precipitate from the water-alcohol mixed solution and drying it for 400 min.
A process of heat treatment and pulverization in a temperature range of ~100''C is performed.

[Operation] In this invention, metal strontium reacts with alcohol to form a strontium alkoxide, and a fine powder material with a uniform particle size can be obtained by simultaneously hydrolyzing the metal alkoxide and the inorganic metal compound. Since the material is a fine powder, its surface activity increases, resulting in improved sinterability.Furthermore, the starting materials in this invention have a precipitated composition due to the fact that their hydrolysis rates are about the same. It is presumed that these effects work together to solve the above-mentioned problems.

〔Example〕

In this invention, metal strontium is reacted with alcohol to form a strontium alkoxide, and the metal alkoxide is hydrolyzed with a water-alcohol mixed solution in which an inorganic zirconium salt is dissolved while keeping water in the minimum necessary amount. The inventors discovered through various experiments that it was possible to obtain a highly pure fine powder with a uniform particle size and composition equivalent to that of aflecoxide alone, and the following reaction conditions were selected. It was done.

In this invention, it is necessary to carry out the steps from the dissolution (first dissolution) of metallic strontium to the hydrolysis and coprecipitation steps in an inert gas atmosphere to avoid the formation of 8rCO as a by-product. In addition, the temperature of the alcohol or alcohol-water mixed solution in the process from dissolving the starting material to hydrolysis must be at least 40°C and below the boiling point of the alcohol. If too much heat is added at the boiling point of the alcohol, the alcohol will boil violently, which is undesirable.Even during hydrolysis, if the temperature is within this range, a precipitate with a uniform composition can be obtained.

As the alcohol solution according to this invention, methyl alcohol, ethyl alcohol, iso-propyl alcohol, n-propyl alcohol, etc. are used. Further, the amount of N in the alcohol for dissolving strontium metal is preferably at least 20 times the amount of Mi in the strontium metal,
It is recognized that if the amount is reduced to some extent, the composition during hydrolysis becomes non-uniform.

The inorganic zirconium salt according to this invention is Zr0 (
NOs)t j Nitrate such as 2HtO・ZrN0s4 or ZrOCl2・8H! A halide such as 0 is used.

Although the molar content of water in the water-alcohol mixed solution in which the inorganic zirconium salt is dissolved (i.e., the water required for hydrolysis in this invention) varies depending on the inorganic salt used in this invention, the target composition (i.e., metallic strontium) It must be at least 1 time and no more than 50 times the amount of the preparation mo/L'l. If it exceeds 50 times, the Sr component in the precipitate may start to re-dissolve and the target composition may not become stoichiometry. Further, it is desirable that the amount of alcohol is equal to or more than the weight of water.

If a water-alcohol mixed solution diluted with less than the same amount of alcohol is used in hydrolysis, water will not be uniformly supplied to the entire solute, and a highly water-containing precipitate will be obtained from a portion of the solute; This precipitate is difficult to filter, so by diluting it with at least the same amount of alcohol as water, a precipitate with uniform particle size can be obtained.

The titanium tetraalkoxide used in this invention is inexpensive, has a GL, and has a suitable viscosity, making it easy to handle, has good solubility in alcohol, etc., and is uniformly dispersed in the precipitate. It can be added. Alternatively, it can be added to the precipitate by dissolving it in a water-alcohol mixed solution containing an inorganic zirconium salt.

As the titanium tetraalkoxide, titanium tetrapropoxide or titanium tetrapoxide is used.

The inorganic titanium salt used in this invention is a halide such as titanium chloride, which is dissolved in alcohol or a water-alcohol mixed solution and added to the precipitate.

The heating treatment temperature after drying the obtained precipitate was 400 to 1o.
The temperature range of oo"o is good. If it is below 400℃, the occluded alcohol will remain and the porosity will increase during the subsequent firing, and if it exceeds 1000℃, the particle size will grow significantly and become reactive. decreases, which defeats the purpose of forming microparticles by the wet method.

As described above, according to the present invention, a fine powder material having a uniform particle size equivalent to that obtained using only metal alkoxide can be obtained. In addition, since it is a fine powder material, the surface activity of 7 increases, resulting in improved sinterability, and SrZr, -
It has a composition of TixO3 (O≦X≦0.15), and a dense sintered body can be obtained by specifically firing at 1600° C. or lower. The above range of X is limited to 0.15 or less, which provides good sinterability and good microwave properties.

By the way, SrZr1−x'r; xo3(O≦X≦0
．． 15) It is known that the temperature coefficient of the dielectric constant of the dielectric ceramic having the composition greatly changes to the negative side as X increases, and the dielectric constant increases. Therefore, in order to make the dielectric constant relatively large and the temperature coefficient small, it is effective to add an additive having a positive temperature coefficient, such as Y2O3.

However, on the other hand, the addition of Y2O3 lowers the sinterability, and when fired at temperatures below 1,600°C, a dense sintered body cannot be obtained and sufficient properties cannot normally be obtained.

In this invention, the above-mentioned problems can be solved because sea urchin is easily sinterable.

Furthermore, uniformity of the precipitate composition due to the fact that the starting materials in this invention have similar hydrolysis rates is also effective for the above purpose.

Next, the present invention is advantageous in terms of cost since it does not use expensive strontium alkoxide, but instead uses relatively inexpensive metal strontium, which easily reacts directly with alcohol to form metal alkoxide. In addition, if the metal alkoxide is expensive or the synthesis of the metal alkoxide is complicated such that a substitution reaction must be performed,
That is, especially in the case of zirconium and yttrium, it is effective to use their inexpensive nitrate monohalides.

This invention will be explained in detail below by giving Examples and Comparative Examples.

Example 1゜The target composition is S, Zro,. 4TiO1,)603
・Gold m Sr, Zr O(N0x)t ・
2 Hz O& (J T t (0cSH7)4 O
Eight starting materials were weighed. Metal Sr, Ti (006
He) A was dissolved in ethyl alcohol with a weight 20 times its total weight, kept at 70°C, and stirred for at least 2 hours downstream in a %Ar gas atmosphere. Next, the mole of the target composition was charged. ! A water-alcohol mixed solution was prepared by diluting 1%, ie, the same mole of water for each mole of metal S, with 3 times the weight of water in ethyl alcohol.This water-alcohol mixed solution was heated. Zr0(No,)2・2HtO
dissolve. Under the same environment as above, this Zr0(NO
x) Water-alcohol mixed bath in which t ・2HtO was dissolved - It was slowly added dropwise to the alcohol/BJ solution in which the above alkoxide was dissolved with vigorous stirring to perform hydrolysis, and the mixture was stirred for 2 hours. Next, the supernatant liquid of the produced precipitate was precleaned by replacing it with alcohol 8 times, followed by solid-liquid separation by filtration or centrifugation gI machine, and dried at 100°C. The obtained precipitate was heat-treated at 600°C for 8 hours to obtain a fine powder.

Example 2゜To obtain a dielectric powder with the same composition as in Example 1, the molar amount of water in a water-alcohol mixed solution was replaced with metal Sr using the same amount of starting materials.
A fine powder was obtained in the same manner as in Example 1 except that the amount of ethyl alcohol was changed to 3 times and 10 times the weight of water accordingly.

Example 3 In order to obtain a dielectric powder with the same composition as in Example 1, the number of moles of water in the water-alcohol mixed solution was changed to 50 times the number of moles of metal Sr, using the same starting material of 7,000 tons, and Accordingly, the amount of ethyl alcohol was changed to 8 times and 50 times the weight of water, and the other conditions were as in Example 1.
A fine powder was obtained in the same manner as above.

Comparative Example 1 Using the same amount of starting materials to obtain a dielectric powder with the same composition as in Example 1, the number of moles of water in the water-alcohol mixed solution was changed to metal S.
A fine powder was obtained in the same manner as in Example 2iii, except that the number of moles of r was changed to 60 times, the ethyl alcohol was changed to 3 times and 60 times the weight of water, and the heat treatment temperature was changed to 750'O.

Comparative Example 2 To obtain a dielectric powder with the same composition as in Example 1, from the same amount of starting materials, the number of water mo/L' in the water-alcohol mixed solution was made 100 times the mo/L/a of metal Sr. A fine powder was obtained in the same manner as in Example 1 except that the amount of ethyl alcohol was changed to 3 times and 100 times the weight of water, and the heat treatment temperature was changed to 750°.

Examples 1-3. The powder obtained in Comparative Example 1.2 was T
EM observation revealed that it was a fine powder of about 100X. Figure 1 is an X-ray diffraction pattern diagram showing the results of Xi diffraction of the obtained precipitate dried at 100°C, where the vertical axis represents the intensity of the diffraction line, and the horizontal axis represents the diffraction angle (2θ). The characteristic curve (a) in the figure represents the diffraction pattern of Example 2.
bl indicates the diffraction pattern of Comparative Example 2. The precipitates of Examples 1 and 8, which were hydrolyzed with 1.50 times as much water as the number of moles of metal Sr, showed the same diffraction pattern as Example 2, which was hydrolyzed with 10 times as much water. Further, the precipitate of Comparative Example 1, which was hydrolyzed with 60 times more water, showed an amorphous diffraction pattern similar to Comparative Example 2, which was hydrolyzed with 100 times more water. Figure 2 is an X-ray diffraction pattern of the fine powder obtained by heat treatment, where the vertical axis represents the intensity and the horizontal axis represents the angle.
Characteristic curves in the figure (cl are those of Examples 1 to 8. Characteristic surface M (
d) is that of Comparative Example 1.2, and a diffraction pattern different from that of SrZrO was obtained.

Comparative Example 8 Dielectric porcelain with the same composition as in Example 1 was used as Srco3°Ti.
Q, and °Z rO, were prepared by a conventional dry method using powders as starting materials. At this time, the starting materials were sufficiently mixed and pulverized using a ball mill, and then calcined at 1150° C. for 2 hours and pulverized. The particle size of this powder was determined by SEM observation to be 0.
It was 5 μm.

Next, compositional analysis of the powders obtained in Examples 1 to 8 and Comparative Example t-3 was performed using fluorescent X-rays. The powders were prepared into a cylindrical shape of 25 m x φ x 5 ittt and were used as samples for analysis. Table 1 shows the relative molar ratio of water used for hydrolysis, S
r/Zr and Tt/Zr are shown. From this result, it can be seen that Examples 1 to 8 have almost the same values as Comparative Example 3. In addition, in Comparative Example 1.2, the ratio of Tl / Zr is almost the same as Comparative Example 3, but sr / Zr is small, and it was found that sr is almost non-existent in 100 times the amount of water. From, hydrolysis kr EEI L/% r
-J'l Sufushi/7'l Jj＆ +斗1:I Nq
An roar 41m ha w-++, spinning 1rIt-h I5
It was found that it must be 0 times or less.

Table 1: Inorganic zirconium salt Zr0CI! - When the same experiment as above was carried out by substituting the /S halogenide of 8H10 and changing the amount of water used for hydrolysis, the same results as in the case of nitrate were obtained.

In addition, it was confirmed that almost the same fine powder could be obtained even if the alcohol was limited to ethyl alcohol and the various alcohols mentioned above were used.

Salani, titanium tetraalkoxide can be added by dissolving it in an acidic water-alcohol mixed bath in which an inorganic zirconium salt is dissolved, and it is completely different from when it is dissolved in alcohol and hydrolyzed as in the above example. It was confirmed by X-ray diffraction that the same precipitate was obtained. It was also confirmed by X-ray diffraction that a similar precipitate could be obtained by replacing titanium tetraalkoxide with titanium chloride and dissolving it in a water-alcohol mixed solution together with an inorganic zirconium salt.

Example 4 For a dielectric body magnet Rg with a non-stoichiometric composition of S "1-δ"o, o4Ti (1,6603), 10XIO≦
A precipitate was obtained under exactly the same conditions and method as in Example 2 using the same starting materials as in Example 2 within the range of δ≦30×10 and heat-treated at 600° C. to obtain a fine powder. Note that l =
Q is the composition of Example 2.

Each of the fine powders synthesized as described above was ro0k
At a pressure of y/7, the diameter is 121111. It was press-molded into a cylindrical shape with a height of 1gff11. The obtained molded body was fired at about 1670° C. for 8 hours in an oxygen atmosphere.

6. Grinding the obtained sintered body. Q mW, φX4
I M with dimensions of 0+uH and 5.8 stop φ x 2.8mmH
Samples were processed for measuring electrical properties at Hz and g GHz. The average temperature coefficient at IMHz, dielectric constant (0 to 60° C.) and Q (reciprocal of microwave loss) at 9 GHz were measured.

Comparative Example 4 For comparison, an attempt was made to obtain a sintered body with the same composition using the conventional dry method, but sufficient sintering was not achieved and the Q (reciprocal of microwave loss) changed significantly due to moisture in the air, causing the material to deteriorate. It was not suitable for evaluation.

So s 8r1-JZro, o+”!o, oeos
-J (7) Dielectric powder was prepared in the same manner as in Comparative Example 8 by adding 0.05 mol of Y2O3 to the composition for II degree coefficient correction and 0.05 mol of each of Mn and O as sintering agents to the main component composition. Next, a molded article similar to that of Example 4 was press-formed by applying a pressure of 700 kg/cnt to 1600°0. After firing for 5 hours, the properties were similarly evaluated.

Figure 8 is a characteristic diagram showing the change in Q as the δ value changes. The vertical axis represents Q and the horizontal axis represents δ value. Although Q is small, δ
As Q became smaller, Q increased, but sinterability tended to deteriorate. When δ (15X10), sintering was difficult and a sufficient sintered body could not be obtained. On the other hand, in Example 2, even when δ = 0, a good sintered body with a high Q, that is, a small microwave loss was obtained. A sintered body is obtained, in particular δ=10.
In X10, good sinterability was obtained even after firing at 1550°C for 14 hours. Although not shown here, the relative dielectric constant and the temperature coefficient of the dielectric constant did not change significantly depending on the value of δ.

As already mentioned, Y2O is added to the SrZr1-xTixO3 system.
By adding 3, the temperature range increases more than K, making it possible to increase X and thus increase the dielectric constant, but on the other hand, the sinterability is significantly lowered. However, as described below, according to the present invention, SrZ containing Y, O,
It was confirmed that the sinterability of r1-XTixO8-based porcelain was improved.

Example 5 Q, 7. - 'l' knee -n-11r 6→
l V-1”I L n 1 engineering +
+,'>(=-+) Example 2
The starting materials and Y (No, )・6H, O were weighed.
D) 4 was dissolved in isopropyl alcohol. Example 2
ZrO(NO3)2.2H20 and Y(NOs)s.
6H20 was dissolved.

Under the same conditions, the water-alcohol mixed solution was added dropwise to the alcohol solution to cause hydrolysis. Thereafter, the sintered body was fired at 1570° C. for 8 hours in exactly the same manner as in Example 4 described above, and the sintered body was processed for characteristic measurement.

Example 6 Solids hydrolyzed and co-precipitated under the same conditions and method as Example 2.
In the liquid mixed solution, Y! with a particle size of 0.5 to 1 μm is added. 0° to 8r
0.1-E-# for Zro, o4Tjo, oaOs
% of iodine and stirred thoroughly. Thereafter, a sintered body was obtained in the same manner as in Example 5, and processed for characteristic measurement.

Comparative Examples 5 to 8 For comparison, dielectric porcelain having the composition shown in Table 2 was used in Comparative Example 8.
It was prepared using a dry method in the same manner as above, and processed for characteristic measurement.

Regarding these (Comparative Examples 3.5 to 8, Examples 2.5.6), we measured the density of the sintered bodies, which is an important factor in terms of FIi characteristics, electrode provision, moisture resistance, dielectric constant, etc. The results are shown in Table 2. In the same table, Comparative Example 3. Comparative example 5
and No. 6, the Q was significantly lowered in air due to humidity. It can be seen that in the conventional method, if a dense sintered body is to be obtained, a decrease in Q is inevitable due to the sintering aid. In contrast, dielectric porcelain fired using fine powder according to the present invention.

Even when Y2O3 is added, a relatively dense sintered body can be obtained.

A high Q value is obtained.

〔Effect of the invention〕

As described above, according to the present invention, the first dissolution step of forming a strontium alkoxide by KiMing the alcohol solution KiM in an inert gas atmosphere at a temperature range of 40° C. or higher and lower than the boiling point of the alcohol; The number of moles of zirconium salt is 1 to 1 of the above metal strontium.
A second dissolution step in which titanium tetraalkoxide or inorganic titanium salt is dissolved in a water-alcohol mixed solution containing 50 times as much water and alcohol as the weight of this water plate, titanium tetraalkoxide or inorganic titanium salt is dissolved in the above alcohol-1 mH, or titanium tetraalkoxide is dissolved in inorganic zirconium salt. or an inorganic titanium salt dissolved in the above water-alcohol solution.
Dissolution step, after the first to eighth dissolution steps, a step of adding the water-alcohol mixed solution to the alcohol solution in the above temperature range in an inert gas atmosphere to hydrolyze and coprecipitate the alcohol solution, and the resulting precipitate. Sr-Zr -Ti- is easily sinterable and has a uniform composition by separating the material from the water-alcohol mixed solution, drying it, and then heat-treating it at a temperature range of 400 to 400°C to make it into a fine powder. 0
This has the effect of obtaining dielectric powder. Therefore, from the obtained fine powder, it is possible to obtain a densified dielectric ceramic with low microwave loss by firing at a temperature of, for example, 1600'0 or less.

[Brief explanation of drawings]

Figure 1 is an X-ray diffraction pattern diagram of the 1,00°C dried product obtained in Example 2 and Comparative Example 2 of the present invention, and Figure 2 is an X-ray diffraction pattern diagram of the 1,00°C dried product obtained in Example 2 of the present invention and Comparative Example 2. FIG. 8 shows the Q(
microwave loss) and Sr1-δZro-e+Tio,
. ,0. FIG. 7 is a characteristic diagram showing the relationship between −δ and δ together with a comparative example. Characteristic curve (a): X-ray diffraction pattern of the 100°C dried product obtained in Example 2 #(bl: Comparative Example 2-(c): X-ray diffraction pattern of the fine powder obtained in Examples 1 to 8 #(d): Comparative Example 1.2 I(e): Characteristic curve l showing the relationship between Q and δ of Example 4
): Comparative Example 4

Claims (7)

[Claims] (1) Strontium metal in an inert gas atmosphere at 40%
A first dissolution step of forming an alkoxide of strontium by dissolving it in the alcohol solution at a temperature range of 1 to 50 times the number of moles of the metal strontium in the above temperature range, and A second dissolution step of dissolving titanium tetraalkoxide or inorganic titanium salt in the above alcohol solution or a water-alcohol solution in which titanium tetraalkoxide and inorganic zirconium salt are dissolved in a water-alcohol mixed solution containing alcohol in a weight greater than water. or a third dissolution step of dissolving the inorganic titanium salt in the water-alcohol solution at the temperature range, and after the first to eighth dissolution steps, mixing the water-alcohol in the alcohol solution at the temperature range in an inert gas atmosphere. A step of adding a solution to hydrolyze and coprecipitate the alcohol solution, and a step of separating the resulting precipitate from the water-alcohol mixed solution, drying it, and then heat-treating it in a temperature range of 400 to 1000°C to form a fine powder. Sr-Z
Method for producing r-Ti-O dielectric powder. (2) The method for producing a Sr-Zr-Ti-O dielectric powder according to claim 1, wherein the first melting step and the third melting step are performed in the same step. (3) The Sr-Zr-Ti-O system according to claim 1 or 2, wherein the inorganic yttrium compound is dissolved or mixed and dispersed in a water-alcohol mixed solution, or mixed and dispersed in a precipitate. Method for producing dielectric powder. (4) The method for producing a Sr-Zr-Ti-based dielectric powder according to any one of claims 1 to 3, wherein the inorganic zirconium salt is a zirconium nitrate or a halide. (5) Sr-Zr- according to any one of claims 1 to 4, wherein the titanium tetraalkoxide is titanium tetrapropoxide or titanium tetrapoxide.
A method for producing Ti-O-based dielectric powder. (6) Sr according to any one of claims 1 to 4, wherein the inorganic titanium salt is a titanium halide.
-Production method of Zr-Ti-O based dielectric powder. (7) S according to any one of claims 3 to 6, wherein the inorganic yttrium compound is one or more of yttrium nitrates, halides, and oxides.
Method for producing r-Zr-Ti-O based dielectric powder.