JPS609327B2 - garnet magnetic material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ferrimagnetic garnet magnetic material for microwave elements such as circulators and isolators used in VHF, UHF, and SHF bands.

In general, the characteristics required of magnetic materials for microwave devices are a narrow Δ day in the ferromagnetic resonance absorption half-maximum, a scale to arbitrarily select an appropriate saturation magnetization value of 4 mms, and a temperature coefficient Q of 4 mms ( 4mMs/ΔT・4mMs) is extremely small.

Yttrium and iron gar are used as microwave materials.
Net (hereinafter abbreviated as YIG) is used. Generally, garnet has the chemical formula {A3}[B2](C3)○,2, where A, B, and C represent elements occupying 24C, 1 ridge, and 2 phantom lattice points, respectively. Particularly in magnetic garnet, magnetic ions occupy some or all of these lattice points. The magnetic arrangement is such that the magnetic moments are coupled in parallel within each sublattice of {A}, [B], and (C), and
) has an antiparallel connection, and {A} and C) have an antiparallel connection. Therefore, the temperature change in saturation magnetization is {A}, [
B], (C) is the vector sum of the temperature changes in the saturation magnetization of the sublattices.

Therefore, in order to reduce the temperature change in saturation magnetization, either the temperature change in each sublattice is reduced by 4, or the temperature change in saturation magnetization as a sum is reduced by 4. Y
In IG, the yttrium ions occupying the 2nd sublattice are non-magnetic, so the difference in changes in the 1st and 24d sublattices becomes the temperature change in total magnetization, which is the temperature coefficient Q of saturation magnetization (-20 to 60
The value of qo) is extremely large, 0.2 to 0.3%°C.

In fact, among the polycrystalline ferrites currently available, Ca, V. ln substitution Y
．． 1. In G, Q reaches as much as 0.4%/00 at -2p to 60°C. For this reason, measures are generally taken in which magnetic shunt steel, magnetic shunt ferrite, etc. are used in combination with the element, or the element is used within a certain temperature range or in a temperature bath. On the other hand, by replacing the non-magnetic yttrium ions with the magnetic gadolinium ions, the magnetic moments of the sublattices are in opposite directions, so they cancel each other out, and the externally observed magnetization value becomes zero. It is known that there is a magnetic cancellation point that looks like this. Since the magnetization becomes zero between this magnetic cancellation point and the Curie temperature Tc, the temperature coefficient of saturation magnetization can be reduced by 4.0 in the temperature range between that point and the Curie temperature Tc. However, △ days are generally large. An example of replacing yttrium with gadolinium ions and improving the temperature coefficients Q and △ of saturation magnetization is A. S. According to Hudson et al.
3-Huanxin Ca2xGda} [Fe2-ZIQ] (Fe3
-ryVXA〆y）○、There is a report of garnet with the composition
g-eyotics, Vol. MAC-5 Lung. 3 196
9P. 610-613). However, the temperature coefficient Q here is at least 0.24%/00, which is not necessarily satisfactory. When used as a microwave device, it is desirable that the temperature coefficient Q of magnetization of the element be small within the temperature range in which it is used. An object of the present invention is to provide a garnet magnetic material that has an extremely small temperature coefficient Q that could not be achieved with conventional materials, and has a small △ day in the half value of ferromagnetic resonance absorption, which indicates the magnetic loss of the material. .

In order to achieve the above object, the present invention has a compositional formula {GLY3
-2X-y-ZCa2X+y}[Fe2-yZry](
Fe3-XVX) ○,2, and in the above composition 0<x≦0.2, 0.3≦y≦0.6, 0.5S
z≦1.8 and 85S8 melon-20 melon 18th place SI20
It is characterized by satisfying the following relationship.

Figure 1 shows the composition formula {GdMYo. Ge x Ca 2 x Small 5}
[Fe,. Zr Misaki] (Fe3-xVx) 08 Vanadium 2 exchange amount and saturation magnetization 4 Ms in garnet represented by 08, ferromagnetic resonance absorption half value △ day and -20 ~
The actual measurement results of the relationship between the saturation magnetization and the temperature coefficient Q at 60 qo are shown.

As is clear from the figure, 4-bamboo Nb decreases linearly with respect to the amount of x substitution. Therefore, the amount of x substitution plays an important role in determining the value of 4Ms. However, the temperature coefficient Q'max of 4 bamboo Nb decreases as the amount of substitution increases, but the ferromagnetic resonance absorption half value Δday increases. Δday has a strong dependence on the amount of y substitution.

However, the x substitution amount is determined by the y substitution amount, which determines the range of the Ca substitution amount. From △day and Q, the amount of substitution is 0
<xSO. It is desirable that it be within the range of 2. Figure 2 shows the composition formula {G too. oYo. 9-Complete C. , 10y} [F
e2-yZry] (Fe2.95V urine) y substitution amount and saturation magnetization 4wM in garnet represented by ○, 2
s, △ day during ferromagnetic resonance absorption half value and -20 of saturation magnetization
The actual measurement results of the function with the temperature coefficient Q at ~60oo are shown.
As is clear from the figure, Q becomes smaller when the amount of y substitution ranges from 0.2 to 0.6. However, if the y substitution amount is less than 0.3, △day will become too large and if the y substitution amount exceeds 0.6, Tc will drop too much, so the y substitution amount should be in the range of 0.3≦y≦0.6. is desirable. Figure 3 shows the composition formula { GLY2
．． , -zCao. 9 }[Fe,. 5Zr ship] (Fe2
．． 8Vo striking 2) Z substitution in garnet expressed as 0,2 and saturation magnetization 4mMs, ferromagnetic resonance absorption half value △
The actual measurement results of the relationship between the temperature coefficient Q and the temperature coefficient Q of saturation magnetization are shown.

As is clear from the figure, the amount of Nb decreases linearly with respect to the amount of z substitution. It can also be seen that the temperature coefficient Q of 4 bamboo NL also decreases monotonically as the amount of z substitution increases. The ferromagnetic resonance absorption at half maximum increases monotonically as the amount of △Kawamaz substitution increases. Figure 4 shows the composition formula {GQY3-2ry-zCaKojuy
} [Fe2-yZry] (Fe3★VX) Temperature T at which 4 momme Ms becomes the maximum in garnet represented by 08
The actual measurement results of the relationship between max and the temperature coefficient Q of 4 mNb between −20 qo and 60 qo are shown.

As is clear from the figure, Tmax is -1000 to 135o.
It can be seen that if the garnet is between 0.0 and 0.0, the temperature coefficient Q of the 4-side Ms can be reduced to 0.1%/°C or less, which is smaller than that of conventional garnet.
Tmax changes by 18°C per x substitution amount of 0.1.

Tmax changes by -20 pm per y substitution amount of 0.1, and z
Tmax changes by 18°C per 0.1 substitution amount. Also x
= 0.0 y 0.4 When z = 2.0, Tmax is approximately 0°C. Therefore, the amount of substitution x, y, z and Tmax
Between 8 melons - 20 18th place - 84 = Tmax...
(1) There is a relationship.

On the other hand, as for the temperature coefficient Q of 4mMs, it is desirable that Tmax is within the range of -10 and 135oo, so each substitution amount is within the range of -10S8-20-18th place where the following formula holds.
84S35... It is desirable that the range satisfies the following relationship.

In addition, the desirable range of the amount of z substitution that satisfies the above conditions is 0.
．． 5SzSI. It is 8. The present invention will be explained in detail below with reference to Examples.

Example 1 Composition formula {G also. oYo. 2-2xC too. 8
12x} [Fe,. 5Zro. 5] (Fe3-xVx)
○d203, Y203, CaC03, Fe203, Z so that the composition becomes x=0.05 0.1 in ○,2
Weigh the raw materials r02 and V2Q and mix them in a ball mill.9
Calcined for 0.5 to 1 feeding time at 0.00 to 1200 oo, crushed again in a ball mill, and after compression molding, 1 at 1250 to 1450 pm.
Fired in an oxygen atmosphere for ~2 hours. The obtained sample is
As a result of line diffraction, it was confirmed that all the materials were single-phase garnet. Using a magnetic balance, the temperature change in saturation magnetization of the obtained sample was measured from the liquid N2 temperature to the Curie temperature. In addition, the ferromagnetic resonance absorption half-value of the sample was measured. The results of these measurements are shown in Table 1. Table 1 Example 2 Composition formula {G too. oY,. 8-yCao. 20y} [F
e2-yZry] (Fe2.$Vo.o5)○,2, a sample was prepared in the same manner as in Example 1 so as to have a composition of y=0.45, and various properties were measured.

Table 2 shows the measurement results.

Table 2 Example 3 Composition formula {GQY2.8-y-zC also. 20y} [Fe
2-yZry] (Fe2.9VM) yi at 0,2
o. Samples were prepared in the same manner as in Example 1 so that the compositions were 45, z = 2.2 and y = 0.5, z = 2.3, and various properties were measured.

Table 3 shows the results. As detailed above, the garnet magnetic material of the present invention has a small △day and an extremely small Q, so there is no need for temperature control using a constant temperature bath, or the control is extremely easy, so its industrial effects are great. be.

[Brief explanation of the drawing]

Figure 1 shows the composition formula {GdMYrut2xCa2x+o.
5} [Fe,. 5Z et al. 5] (Vx to Fe3) A curve diagram showing the relationship between the substitution amount x and various properties at 0.2, Figure 2 is a composition formula {G et al. oYo. 9-yCao. , 10y} [Fe
2-yZry] (Fe2.95V...5) A curve diagram showing the substitution amount y and various characteristics at mountain 2,
FIG. 3 shows the composition formula {G et al Y2. , 1zCao. 9} [Fe
、． 5Zr ship] (Fe2.8Vo.2) 0.2, the curve diagram showing the substitution amount z and various characteristics, Figure 4 is the composition formula {GQ
Y3-2X-y-ZCa Kojuy} [Fe21yZry]
(Fe3★VX) ○, 2 is a curve diagram showing the relationship between the temperature Tmax at which 4Template Ms is maximum and the temperature coefficient Q of 4mMs. Chrysanthemum drawing 2, 3, 4

Claims (1)

[Claims] 1. Compositional formula {Gd_zY_3_-_2_x_-_y_-
＿zCa_2_x_+_y} [Fe_2_−_yZr_
y] (Fe_3_-_xV_x)O_1_2 and in the above compositional formula, 0<x≦0.2, 0.3≦y
A garnet magnetic material characterized by having a composition satisfying the following relationships: ≦0.6, 0.3≦y≦0.6, 0.5≦7≦1.8, and 74≦80x-200y+80z≦120.