JP2622545B2 - Manufacturing method of dielectric resonator material - Google Patents

Description

The present invention relates to a method for manufacturing a dielectric resonator material for microwaves.

[Prior Art] High Q values are required for dielectric resonator materials for microwaves, but particularly high Q values are required for satellite communications and the like.

Ba (Zn _1/3 Nb _{x / 3} T
_{a (2-x) / 3} ) O 3 based ceramic (where 0 ≦ x ≦ 2)
There is.

This ceramic material is generally BaCO ₃ , ZnO, Nb ₂ O ₅ , T
Although it is manufactured by firing a mixed powder containing a ₂ O ₅ as a main component, it is difficult to sinter, and the expected high dielectric constant and Q value are not obtained.

[Problems to be Solved by the Present Invention] In view of the above-mentioned circumstances, the present invention is based on Ba (Zn _1/3 Nb _{x / 3} Ta _(2-x) having a fine structure and improved dielectric constant and Q value. _{/ 3} )
It is an object of the present invention to provide a method for producing O ₃ ceramics.

[Means for Solving the Problems] In the present invention, when producing Ba (Zn _1/3 Nb _{x / 3} Ta _{(2-x) / 3} ) O ₃ -based ceramics, Zn and Zn are first used as a first step.
A mixed solution containing at least one kind of metal component other than Zn, and a content of the metal component other than Zn as a part of the amount necessary for obtaining the target composition, containing at least one kind of metal component other than Ba and Ba. A mixed solution containing the content of the metal component other than Ba as a part of the amount necessary for obtaining the target composition, and containing at least one of Nb and a metal component other than Nb, and containing the metal component other than Nb Prepare one of the mixed solutions in which the amount is a part of the amount necessary for obtaining the desired composition, mix the mixed solution and the precipitate forming solution to form a coprecipitate, and after drying the coprecipitate, , 700-1300 ℃
To obtain a modified powder.

Next, as a second step, the obtained modified powder, a compound powder containing the same residual amount of the metal component as added in the first step, and the remaining metal component necessary for obtaining the target composition And calcined at 700-1700 ° C.

Then, as a third step, the obtained calcined powder is molded and fired at 1200C to 1700C.

In the first step, Ba solution, Zn solution, Nb solution and Ta
As the solution, barium chloride, barium chlorate, barium perchlorate, barium nitrate, barium acetate, barium ethylate, barium isopropylate, zinc chloride, zinc sulfate, zinc nitrate, zinc acetate, niobium chloride, niobium methoxide, niobium Aqueous or alcoholic solutions such as ethylate, tantalum chloride, tantalum alkoxide, and the like may be used. Then, by appropriately mixing these solutions, one of Zn, Ba, and Nb and a mixed solution obtained by adding an appropriate amount of at least one other metal component are obtained, and the mixed solution and the precipitate forming solution are mixed. .

Organic reagents such as ammonia, ammonium carbonate, caustic, oxalic acid, ammonium oxalate, amines and oxines can be used as reagents for forming the precipitate.

The molar ratio between Ba and (Zn _1/3 Nb _{x / 3} Ta _{(2-x) / 3} ) is 1.0
Or an approximate value.

Thus, in the first step, a finely modified submicron-grade powder having good dispersibility can be obtained by calcining the coprecipitate.

In the second step, the modified powder, the compound powder containing the same residual amount of the metal component added in the first step, and the powder of the remaining components necessary for constituting the target ceramic composition are mixed. Mix and calcine. As the powder of the remaining components, it is desirable to use powder having substantially the same particle size as the calcined powder.

Note that a slight amount of a sintering aid can be added in the manufacturing process. Zr, Mg, Sc, Hf, T
h, W, Nb, Ta, Cr, Mo, Ti, Mn, Fe, Co, Ni, Cd, A
l, Sn, As, Bi, Zn, Sr and the like can be used. BaZrO ₃ , BaS
nO ₃ , SrTiO ₃ , BaTiO _{3 and the} like can also be used.

In the first step of the present invention, the calcination temperature of the coprecipitate is 700
When the temperature is lower than 1 ° C, agglomeration occurs. When the temperature exceeds 1300 ° C, the powder particles become coarse.

In the second step, the calcination temperature is required to be not lower than the lowest temperature at which the solid-phase reaction is almost or completely completed, and within the highest temperature range at which no remarkable grain growth occurs.
~ 1300 ° C is desirable. The firing temperature in the third step is 12
If the temperature is lower than 00 ° C., the entire sintering is insufficient. If the temperature is higher than 1700 ° C., the particles become coarse or the constituents are volatilized.

The Ba (Zn _1/3 Nb _{x / 3} Ta _{(2-x) / 3} ) O ₃ ceramics of the present invention comprises Ba (Zn _1/3 Nb _2/3 ) O ₃ and Ba (Zn _1/3 T
a _2/3 ) The calcined powder of O ₃ is prepared by the first and second steps, and the powder is blended so as to have a desired composition, and then calcined in the third step. be able to.

[Effects] In the present invention, however, a submicron-grade modified raw material powder having extremely good dispersibility is obtained in the first step, and this is mixed with another raw material powder to obtain a desired composition raw material. By firing, Ba (Zn
_1/3 Nb _{x / 3} Ta _{(2-x) / 3} ) O ₃ ceramics can be obtained and can be suitably used as a dielectric resonator material.

[Example] 800 cc of barium chloride aqueous solution (1.6 / mol concentration) and 900 cc of zinc chloride aqueous solution (1.8 / mol concentration) were mixed. This mixed aqueous solution was gradually added to 6N-ammonia water 1 with stirring to obtain a hydroxide coprecipitate of Ba ²⁺ and Zn ²⁺ . After washing and drying it, it is calcined at 1100 ° C and BaZnO2
A powder was obtained. The average particle size of the powder was 0.32 μm.

10 g of the powder obtained above (0.0426 mol of BaZnO ₂ )
And commercially available BaCO ₃ fine powder 16.816 g (0.0852 mol), Nb ₂ O ₅ fine powder 9.059 g (0.0341 mol), Ta ₂ O ₅ fine powder 3.765 g (0.0085
2 mol) was mixed in a ball mill for 24 hours, and then calcined at 1000 ° C. for 1 hour to obtain Ba (Zn _1/3 Nb _8/15 Ta _2/15 ) O ₃ powder. The average particle size was about 0.4 μm. A tablet obtained by molding the obtained powder at 1 t / cm ² was fired at 1400 ° C. for 2 hours in the air.

The density, dielectric constant at 9 GHz, and Q value of the obtained ceramic sintered body are shown in the table below.

Comparative Example Commercially available powders of BaCO ₃ , ZnO, Nb ₂ O ₅ , and Ta ₂ O ₅ were mixed with Ba (Zn _1/3 Nb
_8/15 Ta _2/15 ) 25.224 g of BaCO ₃ so as to have a composition of O ₃
(0.1278mol), ZnO and _{3.467g (0.0426mol), Nb 2 O} 5 and 9.
059 g (0.0341 mol) and 3.765 g (0.00852 mol) of Ta ₂ O ₅ were blended, mixed with a ball mill for 24 hours, and then calcined at 1200 ° C. for 1 hour. The average particle size of the calcined powder was about 1.2 μm.

This powder was molded at 1 t / cm ² and fired under the same conditions as in the above example.

The density, dielectric constant, and Q value of the obtained ceramic sintered body are also shown in the following table.

As described above, according to the present invention, Ba (Zn
_1/3 Nb _{x / 3} Ta _{(2-x) / 3} ) O ₃ ceramics can be obtained. The ceramics obtained by the present invention is suitably used as a dielectric resonator material requiring a high Q value.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-269805 (JP, A) JP-A-63-291306 (JP, A) JP-A-63-292507 (JP, A) 29848 (JP, B2)

Claims (3)

(57) [Claims] (1) Ba (Zn _1/3 Nb _{x / 3} Ta) for a dielectric resonator material
_{(2-x) / 3} ) A method for producing an O ₃ -based ceramic (where 0 ≦ x ≦ 2), wherein (1) Zn and at least one metal component other than Zn are contained, and a metal other than Zn is contained. A mixed solution in which the content of the components is a part of the amount necessary for obtaining the target composition, containing at least one kind of metal component other than Ba and Ba, and setting the content of the metal component other than Ba to the target composition A mixture made up of part of the required volume, and
Containing at least one of Nb and a metal component other than Nb;
A mixed solution was prepared in which the content of the other metal components was part of the amount required to obtain the target composition, and the mixed solution and the precipitate forming solution were mixed to form a coprecipitate, The first step of drying the coprecipitate and calcining at 700 to 1300 ° C. to obtain a modified powder, 2. The obtained modified powder, a compound powder containing the same residual amount of the metal component as added in the first step, and a compound powder of the remaining metal component necessary for obtaining a target composition. A second step of mixing and calcining at 700 to 1700 ° C. 3. The powder of the calcined product obtained is molded into a
And b. Sintering at 00 ° C., the method comprising the steps of: