JPH09171918A - Magnetic material for microwave and high frequency circuit component employing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycrystalline ceramic magnetic material wherein a composition to be fired at low temperature is optimized, and a high frequency circuit component employing it. SOLUTION: The microwave magnetic material principally comprises a phase having garnet type structure represented by a chemical formula A3 Bx O12 (where, A contains at least one kind of yttrium Y or rare earth metal element and B contains at least iron Fe) where 4.76<=x<5.00, and A contains bismuth Bi. Alternatively, A contains calcium Ca and bismuth Bi and B contains indium In and vanadium V.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave magnetic material used for a high frequency circuit component and a high frequency circuit component produced by using the same.

[0002]

2. Description of the Related Art In recent years, as seen in the expansion of the market for satellite communication and mobile communication, high-speed and high-density information and communication fields have been developed, and higher frequencies have been used. As a magnetic material used at such a high frequency, a garnet-based magnetic material, which has a high electric resistivity and a small loss at a high frequency, has attracted attention. Also, for high frequency signal processing, a circulator using the gyromagnetic effect of a magnetic material,
There are non-reciprocal circuit devices such as isolators and gyrators, and in this case also, garnet-based magnetic materials are mainly used.

Taking a circulator as a representative of the non-reciprocal circuit device, in a general distributed constant type Y strip line type, a garnet disk is arranged above and below the strip line, and a permanent magnet is sandwiched between the garnet disks from above and below. Has become. The diameter d of the magnetic disk that gives the minimum insertion loss at this time is given by the following equation. d = a / (f · (μ ′ · ε ′) ^0.5 ) where a is a constant, f is frequency, μ ′ is a real number component of relative permeability, and ε ′ is a real number component of relative permittivity. Therefore, the higher the μ'of the magnetic material, the smaller the diameter of the magnetic disk, and the size of the circulator can be reduced. In this case, μ ′ is the forward magnetic permeability μ + ′ due to ferromagnetic resonance, and depends on the strength of the external DC magnetic field. Μ + 'in an external magnetic field directly under the ferromagnetic resonance
Is the maximum, but the loss component μ "is also large and the insertion loss is large. Therefore, it is general to apply an external magnetic field slightly larger than the resonance point and to use it in a state where μ" is not so large. When used in an external DC magnetic field with the same μ ", the smaller the magnetic resonance half-value width ΔH is, the larger μ + 'becomes, which enables downsizing. Even in the case of a smaller lumped constant type, The same applies to the isolator.

On the other hand, the garnet type magnetic material is usually used as a single crystal thin film or a polycrystalline sintered body. Single crystal is produced by the pulling method GGG
900 ℃ by LPE (Liquid Phase Epitaxy) method using (Gadolinium ・ Gallium ・ Garnet) single crystal as substrate
It is generally produced as a thin film at a temperature of about a certain degree.
The sample prepared by this method has a small magnetic resonance half-width ΔH, but it is disadvantageous in that it takes too much time to prepare a sample having a thickness as used in an isolator and is expensive. On the other hand, since a polycrystal is produced as a normal ceramics sintered body, ΔH is one digit or more larger than that of a single crystal, but a sample of any size can be easily produced and is much cheaper than a single crystal. This polycrystalline sintered body has been used for circulators and isolators.

[0005]

However, in general YIG (yttrium iron garnet), Y is replaced with Gd or the like, and Fe is replaced with Al or Ga or the like in order to adjust its saturation magnetic flux density and temperature characteristics. In this case, the firing temperature becomes higher than 1400 ° C and a special furnace is required.
There was also a problem in terms of energy saving.

Further, as easily estimated in the structure of the circulator described above, the magnetic flux generated by passing a current through the strip line alternately passes through the magnetic body and the gap between the magnetic body and the open magnetic circuit. For this reason, the apparent magnetic permeability is affected by the void portion (μ ′ = 1), and has a drawback that the magnetic permeability is lower than the original magnetic permeability. In order to prevent this drawback, it is necessary to have a closed magnetic circuit structure, and a method of embedding a conductor in a magnetic material and firing it at the same time has also been devised (Shingaku Giho, MW94-14, P17 (1994)). However, in this method, the firing temperature of garnet is 14
Since it is as high as 00 ° C., it is necessary to use palladium or the like having a high melting point as an internal electrode, and since palladium is expensive and has a relatively high electric resistivity, there are problems that the cost is high and the Q is low.

Also, when used as a high frequency inductor, in order to obtain a small size and a high inductance value, it is necessary to incorporate an electrode material into a closed magnetic circuit structure (published by the Industrial Research Institute, "Micro Magnetic Device All ”P176
-177), there is a problem that the cost is high and the Q is low for the same reason as the circulator.

In order to solve the above-mentioned conventional problems, it is an object of the present invention to provide a polycrystalline ceramic magnetic material having an optimized composition that can be fired at a low temperature, and a high frequency circuit component using the same.

[0009]

In order to solve the above problems, the material of the present invention has a garnet type structure and has a chemical formula of A ₃ B _x O ₁₂ (where A is at least yttrium (Y) or Contains at least one rare earth metal element, B
Is at least iron (Fe)), and x is a magnetic material material for microwaves containing as a main component a phase of 4.76 ≦ x <5.00. The material of the present invention is a magnetic material for microwaves, wherein A contains bismuth (Bi). Further, in the material of the present invention, A contains calcium (Ca) and bismuth (Bi), and B contains iron (Fe) and indium (I).
n) and vanadium (V), which is a magnetic material for microwaves. Further, the material of the present invention contains a phase having a garnet structure as a main component, and as a sub-component, the main component is 100 parts by weight, and vanadium (V) is converted into V ₂ O ₅ parts by weight, and 0 < V ₂ O ₅ ≦ 1, copper (Cu) in terms of CuO weight part, 0 <CuO ≦ 1,
Converting molybdenum (Mo) to parts by weight of MoO ₃ 0 <
Includes one or more of MoO ₃ ≦ 1, tungsten (W) in terms of WO ₃ by weight of 0 <WO ₃ ≦ 1, and lead (Pb) in terms of PbO by weight of 0 <PbO ≦ 1. It is a magnetic material for microwaves that is characterized. Further, the high-frequency circuit component of the present invention is a high-frequency circuit component characterized in that a conductor is embedded in the magnetic body to form a closed magnetic circuit.
The high frequency circuit component of the present invention is a high frequency non-reciprocal circuit device. In this element, it is desirable that the conductor in the magnetic body contains silver (Ag) as a main component.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below by taking YIG as an example of a representative garnet.

(Embodiment 1) As a starting material, Y
₂ O ₃ , Bi ₂ O ₃ , α-Fe ₂ O ₃ , and V ₂ O ₅ powder are used.
These powders were blended in the chemical formula Y _{3 over y} Bi y Fe _x O ₁₂ composition ratio represented, was added 0.1wt% V ₂ O ₅ as an additive, was calcined at 850 ° C., again Smash. The value of x is 4.76 ≦ x <5.00, and the value of y is y <
It is 2.00. After molding this calcined powder, it was fired at a predetermined temperature for 3 hours. The obtained sample is a magnetic material having a garnet structure. As the Bi amount y increases,
Densify at lower temperatures. However, as a result of determining the presence or absence of the second phase by powder X-ray diffraction, the Bi substitution amount y is 2.
When it is 0 or more, or when the Fe amount x is 4.70 or less, or when the Fe amount x exceeds 5.00, the garnet does not become a single phase, and the presence of the second phase is recognized. When the amount of Fe is 5.00, a single phase is obtained, but a low loss is obtained in a composition in which the amount of Fe is less than the stoichiometric composition ratio. The same effect can be obtained even if the additive is added after calcination.

(Embodiment 2) As a starting material, Y
₂ O ₃ , α-Fe ₂ O ₃ , V ₂ O ₅ , and CuO powder are used. These powders are blended in a composition ratio represented by the chemical formula Y ₃ Fe _x O ₁₂ + zwt% V ₂ O ₅ , calcined at 1100 ° C., and then pulverized again. The value of x is 4.76 ≦ x <5.00,
The value of z is z <2.0. After molding this calcinated powder, it is fired at each predetermined temperature for 3 hours. The obtained sample is a magnetic material having a garnet structure. As the value of z becomes larger, the density becomes higher at a lower temperature. However, as a result of determining the presence or absence of the second phase by powder X-ray diffraction,
When the added amount z of V ₂ O ₅ is 2.0 or more, the Fe amount x is 4.70 or less, or the Fe amount x exceeds 5.00, the garnet single phase does not occur and the second phase is present. Is recognized. The same effect can be obtained even if the additive is added after calcination.

(Embodiment 3) As a starting material, Y
₂ O ₃ , Bi ₂ O ₃ , CaCO ₃ , α-Fe ₂ O ₃ , In
₂ O ₃ and V ₂ O ₅ powder are used. These powders have the chemical formula Y
₃ incorporated into _{chromatography (2x + z) Bi z Ca} 2x Fe p- (x + y) In y V x O 12 composition ratio represented, after calcining at 850 ° C., pulverized again. Variable values are x ≦ 0.8, y ≦ 0.7, z <2.
00, p4.76 ≦ p− (x + y) <5.00, where 2x + z ≦ 2.5. After molding this calcined powder,
It was baked at a predetermined temperature for 3 hours. The obtained sample is a magnetic material having a garnet structure. As the Bi amount z increases, the density is increased at a lower temperature. However, as a result of determining the presence or absence of the second phase by powder X-ray diffraction, the Fe amount p- (x + y) is 4.70 or less, or the Fe amount p-
When (x + y) exceeds 5.00, the garnet single phase is not formed and the presence of the second phase is recognized. Fe content p- (x +
When y) is 5.00, although it is a single phase, good crystallinity can be obtained in a composition in which the amount of Fe is less than the stoichiometric composition ratio. Further, in the composition in which x is 0.2 ≦ x ≦ 0.6 and y is 0.3 ≦ y ≦ 0.6, the one with less loss can be obtained. The same effect can be obtained even if the additive is added after calcination.

(Embodiment 4) As a starting material, Y
_TwoO_Three, Bi_TwoO_Three, Α-Fe_TwoO_Three, V_TwoO_Five, CuO, Mo
O _Three, WO_Three, PbO powder was used. These powders,
Formula Y_3-yBi_yFe_xO₁₂Blended to the composition ratio represented by
V as an additive_TwoO_Five, CuO, MoO_Three, WO_Three, PbO
Add any of the above, calcinate at 850 ℃, then crush again
I do. The value of x is 4.76 ≦ x <5.00, the value of y
Is y <2.00. After molding this calcined powder,
It was baked at a predetermined temperature for 3 hours. The obtained sample is
It is a magnetic material with a structure. Bi amount y increases
Therefore, it densifies at a lower temperature. 90% or more density
The firing temperature at which_TwoO_FiveAt 1250 ° C, CuO
At 1250 ° C, MoO_ThreeAt 1250 ° C, WO_ThreeThen 1
The temperature is 300 ° C., and that of PbO is 1300 ° C. With the same additives
Is Fe_TwoO_ThreeIt is constant regardless of the amount. However, the powder
The presence or absence of the second phase was determined by terminal X-ray diffraction.
The exchange amount y is 2.0 or more, or the Fe amount x is 4.70 or more.
Underneath, or when the Fe content x exceeds 5.00,
The presence of a second phase is recognized, instead of a single phase. Fe amount
Is 5.00, it is a single phase, but Fe content is stoichiometric
The composition with less loss is obtained in the composition less than the theoretical composition ratio.
Can be V as an additive_TwoO_Five, CuO, MoO_Three, W
O_Three, PbO, effective for densification at low temperature
Is V_TwoO_Five, CuO addition is more effective. In addition,
Similar effects can be obtained by adding additives after calcination.

(Embodiment 5) As a starting material, Y
₂ O ₃ , Bi ₂ O ₃ , α-Fe ₂ O ₃ , and V ₂ O ₅ powder are used.
These powders are blended in a composition ratio represented by the chemical formula Y ₂ BiFe _4.88 , V ₂ O ₅ is added as an additive at a ratio of 0.1 wt%, calcined at 850 ° C., and then pulverized again. After this calcined powder is molded, it is fired at 900 ° C. to obtain a garnet disk-shaped sample. This disc-shaped sample is placed above and below the strip line, sandwiched by magnets from above and below, placed in a metal case, and a resistor for terminator is connected to one end of the strip line to form a distributed constant type Y strip line isolator. To do. 1 GHz of the obtained isolator
As a result of measuring the insertion loss in the positive direction at 0.28 dB. By controlling the amount of Fe precisely, it becomes densified at a much lower temperature than before without the presence of the second phase.
It can be sintered even at a temperature of 00 ° C. or less, has an insertion loss of 0.5 dB or less, and can be used as an isolator.

(Embodiment 6) As a starting material, Y
₂ O ₃ , Bi ₂ O ₃ , α-Fe ₂ O ₃ , and V ₂ O ₅ powder are used.
These powders are blended in a composition ratio represented by the chemical formula Y ₂ BiFe _4.88 , CuO is added as an additive at a ratio of 0.1 wt%, calcined at 850 ° C., and then pulverized again. After mixing an organic binder with this calcined powder and forming a uniform green sheet by the reverse roll coater method,
The green sheet is cut into a circle. On the other hand, a conductive paste prepared by mixing Ag with an ethylcellulose-based vehicle is prepared and printed as a strip line on the green sheet. Prepare 3 sheets of the same product, stack them so that the strip lines intersect with each other at an angle of 120 degrees, stack 1 sheet of green sheet on top of it, and apply pressure in the thickness direction to crimp them, and then magnetic layer 4 layers A green sheet laminate in which three conductors are sandwiched is prepared. This is 90
It is fired at 0 ° C. so as to have a closed magnetic circuit configuration, and Ag paste is applied to the position of the internal conductor on the side surface of the sintered body.
External electrodes are formed by baking at 0 ° C. Of the electrodes of this laminated body, three places that are 120 degrees apart from each other are grounded, and one of the other three places is grounded and terminated through a matching resistor, and the other two places are properly connected to terminals. A 1.9 GHz lumped-constant type isolator is manufactured by providing a load capacitance, sandwiching it from above and below with a magnet, and holding it in a magnetic metal case.

In the same manner, the amount of Fe and additives (V
A lumped constant type isolator using an electrode material of either Ag or Pd is prepared by using garnet having a different compounding amount of ₂ O ₅ or CuO). For comparison, an open magnetic circuit configuration lumped constant isolator, in which a magnetic material and an electrode are separately arranged, is also manufactured for comparison. The magnetic material size is the same in both cases. The isolation ratio band (frequency bandwidth at which isolation of 20 dB or more / maximum isolation frequency) and the insertion loss of the obtained isolator are measured. The closed magnetic circuit configuration has a wider specific band than the open magnetic circuit configuration. Since the magnetic substance containing V ₂ O ₅ or CuO and Bi according to the present invention can be precisely controlled in the amount of Fe and can be fired at 900 ° C., simultaneous firing / closed magnetic circuit configuration can be achieved by using Ag as an internal electrode. As a result, a wide bandwidth and a low insertion loss can be obtained. If the Fe content is too large or too small, V ₂ O ₅ or C
The insertion loss increased a little regardless of the content of uO or the type of electrode material. This is because the densification of the sintered body is not sufficient at 900 ° C. firing due to the excess and deficiency of Fe, and the relative density is lowered due to the presence of the second phase.
This is probably because the loss becomes large. Further, the Fe content is slightly smaller than the stoichiometric composition ratio, and is 4.82 ≦ Fe ≦ 4.94.
In between, a product with small insertion loss and good characteristics can be obtained.

On the other hand, in the case of a normal YIG which does not contain V ₂ O ₅ or CuO and Bi, in the Ag internal electrode simultaneous firing / closed magnetic circuit configuration, even if the Fe content is precisely controlled, it does not become an isolator. This is considered to be because the YIG hardly densified when the temperature was low, while the YIG densified when the temperature increased, but the electrode was cut off because the melting point of Ag was significantly exceeded. In this case, if Pd is used as an internal electrode and fired at 1400 ° C., it is possible to obtain the one having quite good characteristics, but there are disadvantages that Pd is expensive, requires high temperature firing, and has a slightly large insertion loss.

In the above description, YIG was mainly taken as an example, but the present invention is not restricted to this, and its saturation magnetic flux density and temperature characteristics are adjusted so that it is often performed with garnet materials. In order to achieve
The same effect can be observed with the case of substituting with or the case of substituting Y with Gd. Further, a Y stripline type isolator of a non-reciprocal circuit element will be described as an example of a high-frequency component, but the present invention is not restricted to this, and other types of high-frequency circuit components can also be used.
It is a product that can obtain exactly the same effect.

Next, a specific example of the present invention will be described. (Example 1) As a starting material, Y having a purity of 99.9%
₂ O ₃ , Bi ₂ O ₃ , α-Fe ₂ O ₃ , and V ₂ O ₅ powder were used.
These powders were mixed with Y ₂ O ₃ amount 3-y, Bi ₂ O ₃ substitution amount y,
Fe ₂ O ₃ amount x becomes the value of (Table 1), and the total weight is 300
and added V ₂ O ₅ as an additive in an amount of 0.1 w
t% was added, mixed in a ball mill, calcined at 850 ° C. for 2 hours each, and then pulverized again in the ball mill. After this calcinated powder was molded, it was fired at each predetermined temperature of 50 ° C. for 3 hours. The relative densities of the obtained samples were measured, and the results of determining the presence or absence of the second phase by the minimum firing temperature at which a relative density of 90% or more was obtained and the powder X-ray diffraction are shown in (Table 1).

[0021]

[Table 1]

As is clear from (Table 1), the magnetic substance of the present invention was densified at a lower temperature as the substitution amount of y increased. However, if the Bi substitution amount y is 2.0 or more, or the Fe amount x is 4.70 or less, or F
When the amount x exceeds 5.00, the garnet single phase was not formed and the presence of the second phase was recognized. When the amount of Fe was 5.00, it was a single phase, but in the composition in which the amount of Fe was less than the stoichiometric composition ratio, the one having excellent crystallinity was obtained.

(Example 2) As a starting material, a purity of 99.
9% Y ₂ O _3, with _{α-Fe 2 O 3, V} 2 O 5, CuO powders. These powders were blended so that Y ₂ O ₃ = 3, the amount of Fe ₂ O ₃ x was (Tables 2 and 3) and the total weight was 300 g, and V ₂ O ₅ and CuO were added as additives. Was added at a ratio of (Tables 2 and 3) and mixed by a ball mill,
After calcination at 1100 ° C. for 2 hours each, it was pulverized again with a ball mill. After this calcinated powder was molded, it was fired at each predetermined temperature of 50 ° C. for 3 hours. The relative densities of the obtained samples were measured, and the results of determining the minimum firing temperature at which a relative density of 90% or more and the presence or absence of the second phase are shown (Tables 2 and 3).

[0024]

[Table 2]

[0025]

[Table 3]

As is clear from (Tables 2 and 3), the magnetic substance of the present invention was densified at a lower temperature as the added amount of z increased. However, when the added amount of V ₂ O ₅ z is 2.0 wt% or more, the Fe amount x is 4.70 or less, or the Fe amount x exceeds 5.00, the garnet single phase does not occur and the second phase The existence of When the amount of Fe was 5.00, it was a single phase, but in the composition in which the amount of Fe was less than the stoichiometric composition ratio, the one having excellent crystallinity was obtained. The same effect was obtained even if the additives were added after calcination.

(Example 3) As a starting material, a purity of 99.
9% Y ₂ O ₃ , Bi ₂ O ₃ , α-Fe ₂ O ₃ , V ₂ O ₅ , Cu
O, MoO ₃ , WO ₃ , and PbO powders were used. These powders were blended so that Y ₂ O ₃ = 3, the Fe ₂ O ₃ amount x was (Table 4) and the total weight was 300 g, and V ₂ O ₅ , CuO and MoO were added as additives. ₃ , WO ₃ , PbO were added at a ratio of 0.1 wt% and mixed by a ball mill,
After calcination at 850 ° C. for 2 hours each, it was ground again with a ball mill. After this calcinated powder was molded, it was fired at each predetermined temperature of 50 ° C. for 3 hours. The relative densities of the obtained samples were measured, and the minimum firing temperature at which a relative density of 90% or more was obtained and the presence / absence of the second phase are shown in (Table 4).

[0028]

[Table 4]

As is clear from Table 4, the magnet of the present invention is
In sex, V_TwoO_Five, CuO, MoO _Three, WO_Three, Of PbO
If either of them is added, the same additive is used as Fe._TwoO_ThreeIn quantity
The firing temperature is constant regardless. However, eventually
The Fe content x is 4.70 or less in the additive of
If the Fe content x exceeds 5.00, the garnet single phase is
However, the presence of the second phase was recognized. Fe amount is 5.00
In the case of, although it is a single phase, the Fe content is higher than the stoichiometric composition ratio.
It is possible to obtain excellent crystallinity with less composition.
Was. Additive V_TwoO_Five, CuO, MoO_Three, WO_Three, PbO
Are effective for densification in low temperature firing,
V_TwoO_Five, CuO addition was effective. The additives are
Similar effects were obtained even if added after calcination.

Example 4 As a starting material, a purity of 99.
9% Y_TwoO_Three, Bi_TwoO_Three, Α-Fe_TwoO_Three, V_TwoO_FivePowder
Using. These powders are_TwoO_Three, Bi_TwoO_Three, Fe_TwoO_Three
The mol ratio of (Y _TwoO_Three+ Bi_TwoO_Three): Fe_TwoO_Three= 3:
4.88, Y_TwoO_ThreeAnd Bi_TwoO_ThreeThe molar ratio of Y / B
i = 2/1 value so that the total weight is 300g
And V as an additive_TwoO_FiveAt a ratio of 0.1 wt%
Add, mix in a ball mill and calcine at 850 ° C for 2 hours
After that, it was crushed again with a ball mill. Form this calcinated powder
After shaping, calcination at 900 ℃ for 3 hours, outer diameter 25mmφ, thickness
A 1.5 mm garnet disk-shaped sample was obtained. This disk shape
Place the sample above and below the Y-shaped stripline, and
Sr ferrite disc from above and below, magnetic metal case
And a terminator at one end of the stripline
Constant resistance type Y strip line eye
Configured the Solator. 1 GHz of the obtained isolator
As a result of measuring the forward insertion loss at 0.28 dB
Was. For comparison, Fe_TwoO_Three= 5.00 isolators
, The insertion loss was 0.35 dB.

The magnetic material of the present invention can be densified at a much lower temperature than the conventional one by controlling the amount of Fe precisely, and can be sintered even at 900 ° C. or less, It could be used as an isolator with an insertion loss of 0.5 dB or less.

(Embodiment 5) In the same manner as in Embodiment 1, Y
₂ O ₃ : Bi ₂ O ₃ : Fe ₂ O ₃ = 2: 1: 4.88 mol
The ratio was such that the total weight was 300 g, 0.1 wt% of CuO was added as an additive, mixed in a ball mill, calcined at 850 ° C. for 5 hours, and then pulverized again in the ball mill. An organic binder was mixed with the calcined powder to form a uniform green sheet by a reverse roll coater method, and then the green sheet was cut into a circle. On the other hand, a conductive paste made by mixing Ag with an ethyl cellulose-based vehicle was prepared and printed as a strip line on the green sheet. Prepare 3 sheets of the same product, stack them so that the strip lines intersect with each other at an angle of 120 degrees, stack 1 sheet of green sheet on top of it, and apply pressure in the thickness direction to crimp them, and then magnetic layer 4 layers A three-layered green sheet laminate of conductors was prepared. This was fired at 900 ° C. for 3 hours to form a closed magnetic circuit, and the position 6 of the inner conductor on the side surface of the sintered body was used.
An external electrode was formed by applying Ag paste to various places and baking at 700 ° C. for 10 minutes. Out of the 6 electrodes of this laminated body, 3 of which are 120 degrees apart from each other are grounded, and 1 of the 3 other electrodes is grounded and terminated through a matching resistor, and the other 2 terminals are connected to terminals. Then, an appropriate load capacity was provided, and it was sandwiched from above and below by a magnet disk and placed in a magnetic metal case to manufacture a 1.9 GHz lumped constant isolator.

A lumped constant type isolator using the garnet composition and electrode material shown in (Table 5) was prepared by the same method. For comparison, an open magnetic circuit configuration lumped constant isolator, in which a magnetic material and an electrode were separately arranged, was also manufactured for comparison. The magnetic material size was the same in both cases. The isolation ratio band (frequency bandwidth at which isolation of 20 dB or more / maximum isolation frequency) and the insertion loss of the obtained isolator were measured. The results are shown in (Table 5).

[0034]

[Table 5]

As is clear from (Table 5), in the closed magnetic circuit configuration, the specific band is wide. In the present invention, the amount of Fe is precisely controlled and the magnetic substance containing V ₂ O ₅ or CuO and Bi is
Since it can be fired at 900 ° C., it is possible to perform simultaneous firing / closed magnetic circuit configuration using Ag as an internal electrode, and as a result, a wide specific band and low insertion loss were obtained. When the amount of Fe was too large or too small, the insertion loss increased a little regardless of the kind of additive or the kind of electrode material. It is considered that this is because, due to the excess and deficiency of Fe, sintering at 900 ° C. does not sufficiently densify the sintered body and the sinterability is insufficient, resulting in a large loss. Also, F
The amount of e is slightly smaller than the stoichiometric composition ratio 4.82 ≦ Fe ≦
Between 4.94, the one with small insertion loss and good characteristics was obtained.

(Embodiment 6) In the same manner as in Embodiment 1, Y
_TwoO_Three: Bi_TwoO_Three: CaCO_Three: Fe_TwoO_Three: In_TwoO _Three: V_Two
O_Five= 0.8: 1.4: 0.8: 4.18: 0.3:
The molar ratio will be 0.4, and the total weight will be 300 g.
Seaweed, mix in a ball mill and mix at 850 ° C for 5 hours
After calcination for a while, it was crushed again with a ball mill. This calcined powder
A lumped-constant type isolator is manufactured with the same method as in the fifth embodiment.
Was prepared.

A lumped constant isolator having a garnet composition shown in (Table 6) was produced in the same manner. The isolation ratio band (20
Frequency bandwidth that can obtain isolation of dB or higher /
The maximum isolation frequency) and insertion loss were measured.
The results are shown in (Table 6).

[0038]

[Table 6]

As is clear from (Table 6), F of the present invention
Since the amount of e can be precisely controlled and the magnetic substance containing Bi, Ca, In, and V can be fired at 900 ° C., it is possible to use simultaneous firing / closed magnetic circuit configuration with Ag as an internal electrode. A wide bandwidth and low insertion loss were obtained. When the Fe content was too large or too small, the insertion loss was slightly increased. This is due to excess and deficiency of Fe, 900 ℃
It is considered that the firing increases the loss due to insufficient densification of the sintered body and insufficient sinterability. Further, the Fe content is slightly smaller than the stoichiometric composition ratio, 4.12 ≦
When Fe ≦ 4.24, a material having a small insertion loss and good characteristics was obtained.

[0040]

As described above, the present invention is a microwave garnet ferrite sintered body that can be fired at a low temperature. Moreover, it is a high frequency circuit component using this. According to the present invention, a high-frequency garnet can be easily manufactured,
Further, since it can be fired at 900 ° C. or lower, it can be fired simultaneously with the electrode material and, for example, the dielectric material, and a high-performance and small-sized high-frequency circuit component can be obtained.

Claims (7)

[Claims] 1. A garnet type structure having a chemical formula of A ₃ B _x O
₁₂ (wherein A includes at least one type of yttrium (Y) or rare earth metal element, and B includes at least iron (Fe)), and x is 4.76 ≦ x <5.00 A magnetic material for microwaves that has a phase as a main component. 2. The magnetic material for microwaves according to claim 1, wherein A contains bismuth (Bi). 3. A is calcium (Ca) and bismuth (B)
2. The magnetic material for microwaves according to claim 1, characterized in that B is composed of iron (Fe), indium (In) and vanadium (V), including i). 4. A phase having a garnet-type structure as a main component, and the main component as an auxiliary component, 100 parts by weight,
Converting vanadium (V) to parts by weight of V ₂ O ₅ 0 <V ₂
O ₅ ≦ 1, copper (Cu) is converted to CuO weight part and 0 <
CuO ≦ 1, molybdenum (Mo) is converted to the weight part of MoO ₃ , and 0 <MoO ₃ ≦ 1, tungsten (W) is WO ₃
Converted to parts by weight of 0 <WO ₃ ≤1, lead (Pb) is Pb
The magnetic material for microwaves according to claim 1, 2 or 3, which contains one or more kinds of 0 <PbO ≦ 1 in terms of O weight part. 5. A high-frequency circuit component comprising the magnetic body according to claim 1, wherein a conductor is embedded in the magnetic body to form a closed magnetic circuit. 6. The circuit component according to claim 5, wherein the high frequency circuit component is a high frequency non-reciprocal circuit device. 7. The high frequency circuit component according to claim 5, wherein the conductor in the magnetic material contains silver (Ag) as a main component.