JPS5853496B2 - Micro flywheel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ferrimagnetic material suitable as a ferrite for microwave circuit elements, particularly for latching phase shifters.

Conventionally, garnet-based ferrites and their substitutes have been used as ferrites for latching phase shifters in the microwave frequency band. ] In recent years, lithium ferrite and its substituted products have come to be used.

This lithium-based ferrite magnetic material has excellent temperature characteristics and squareness, and has various advantages such as being lightweight and inexpensive, but on the other hand, it has inferior power durability compared to garnet-based ferrite doped with rare earth elements. There were drawbacks.

Here, the power withstand characteristics of microwave ferrite are expressed by the minimum microwave magnetic field he that causes nonlinearity and the resonance half-width JHk of the spin wave obtained from this he. As a method of increasing the resonance half-width JHk of lithium-based ferrite, that is, a method of improving the power durability characteristic which is a drawback of lithium-based ferrite, a method of replacing lithium-based ferrite with Co is known.

However, although this Co-substituted or Tuum ferrite-substituted material improves the power resistance, it has the disadvantage that the coercive force Hc increases and the squareness ratio decreases.

As a result of conducting various studies in view of these drawbacks, the present invention has developed a ferrimagnetic material for microwaves containing lithium-based ferrite and one or more of Ho and Dy, which has excellent power resistance characteristics and squareness ratio, and has excellent resistance to electricity. The present invention provides an inexpensive magnetic material with a small magnetic force Hc.

The present invention is based on the scientific formula L l □, 5 Fe 2.504
This is a ferrimagnetic material for microwaves containing 0.02 mol or less of one or more of Ho and Dy in the substituent represented by lithium ferrite@Mn alone or substituted with Zn and Ti.

To explain the present invention in more detail below, in the present invention, both Ho and Dy are the most effective elements for improving high power characteristics and squareness ratio. The resonance half-width JHk is increased, that is, the high power characteristics are improved.

In addition, the squareness ratio is replaced by Mn or Ho in the case of thium-based ferrite.

As Dy increases, E gradually increases, shows a peak, and then decreases, but in the case of Zn and Ti substituted or Tuum-based ferrite, the rate at which the squareness ratio decreases compared to one substituted with other metals is higher. is extremely small and remains constant at approximately 0.6.

In this case, replacement with Ti alone is not possible.

The reason for this is that Ti is tetravalent, and Ti alone cannot cancel out the charge of trivalent Fe in the ferrite.

Therefore, adding 1/2(Zn+Ti) (trivalent) cancels out the charge f with the trivalent Fe in the ferrite.

In addition, in the present invention, the amounts of Dy and Ho added are the same as 1 above.
The reason for limiting the amount to 0.02 mol or less in the chemical formula is that 0.02
This is because when the molar ratio exceeds 1/2 (
This is because, in the case of Zn + Ti) or in the case of tium-based ferrite, when the squareness ratio becomes constant, the coercive force Hc increases.

Next 1 Method E for producing the ferrimagnetic material of the present invention
To explain briefly, L 1203 s Fe 203 forms a lithium-based ferrite and MnCo3. ZnO, TiO2.

Various high purity powders such as Dy2O3 and He203 are mixed with the above [
After weighing so that the ratio f corresponds to the chemical composition and mixing and pulverizing it in a ball mill, the mixed powder is
It is roasted at a temperature of 1000° C. for 4 to 6 hours, and then ground again to obtain a roasted powder.

Next I The powder is pressurized into an acid form using a desired mold, and then fired at 900 to 1200° C. for 8 hours in an oxygen atmosphere to produce a ferrimagnetic material having a desired shape.

Embodiment E of the present invention will be explained below.

Example 1 “Equation Lj0.5-1./!XFe2,5-IAX,
In the composition I represented by M n X Dy, 04,
With X=0.05 and Y changed by 1, the composition E is as follows: Li2CO3, Fe2032MnCO3 and Dy2O
After mixing and pulverizing the high-purity powders of 3, they were roasted at 700°C for 4 hours.

Furthermore, the mixed powder obtained by pulverizing this powder was pressure molded in a mold, and then fired in an oxygen atmosphere for 1 to 16 hours using a trowel at 900 to 1150° Cf to prepare a cylindrical test piece.

Using the ferrimagnetic material test piece obtained in this way, the resonance half-width JHK of the spin wave, which exhibits the power-withstanding characteristics, and the magnetic
Ferromagnetic resonance half-width JH indicating the squareness ratio, coercive force Hc, and magnetic loss determined from the H curve.

were measured, and the results are shown in the graphs of FIGS. 1 to 4.

Note that the resonance half-width JHk of the spin wave mentioned above is obtained by finding the minimum microwave magnetic field hc using the parallel excitation method at 9.2 GHz with respect to the minimum ferromagnetic resonance half-width JH, and then finding JHk from this. 1. (It is expressed by the relationship Hk=hc.

Here, ωM-γ(4πMs), γ is the gyromagnetic ratio, and ω is the microwave angular frequency.

In addition, using this test piece, the sample vibrating magnet was measured with a saturation magnetic ratio of 4πMs, Curie 1 temperature Tc, dielectric constant ε,
As a result of measuring the dielectric loss tan δe and the dielectric loss tan δe, the results were almost the same as those of the conventional lithium-based ferrite which is not substituted with Dy.

From the results shown in Figures 1 to 4, JHk has a Dy of 0.02.
It was found that by adding moles, the power consumption increased by about 1.5 times, and when this was converted into a custom-made power resistance, it was improved by about 2.4 times.

Furthermore, the squareness ratio reaches its maximum value when about 0.01 mol is added, and on the other hand, the increase in coercive force H can be suppressed slightly.

Example 2 F'e1.
The composition I represented by 19DyTi6.8□04 with y changed to 0.025 was crushed and fired in the same manner as in the above example to prepare a cylindrical test piece.

Using the ferrimagnetic material test piece obtained in this way, the minimum microwave magnetic field hc exhibiting power-withstanding characteristics (However, since this ferrimagnetic material has a small saturation magnetic f 4πMs,
Power resistance characteristics are expressed by hc), squareness ratio, coercive force H
c, and the ferromagnetic resonance half width JH are determined and shown as solid lines in graphs I in FIGS. 5 to 8, respectively.

In addition, in Fig. 5, the minimum microwave magnetic field hc is 45 (O
The magnetization curve of the ferrimagnetic material containing 0.02 mol of Dy, shown in e), was determined and is shown as a solid line in the graph l of FIG.

Comparative Example In the set 6t shown in Example 2 above, Dy is replaced with Co.Fhi Scientific formula L10.885 Zno, o5 F'el
-19 COT l g , the ferrimagnetic material f shown by 6204 was difficult, but y was changed to 0.04 and the characteristics of t were investigated in the same manner as in Example 2 above.

The results are as shown by broken lines in the graphs of FIGS. 5 to 9.

As is clear from the graphs of FIGS. 5 to 9, it was confirmed that the material according to the present invention is superior in each characteristic to the ferrimagnetic material substituted with Co.

In the above Example E, the substitution with Dy is shown, but the substitution with Ho also has the same effect.

As explained above, the ferrimagnetic material of the present invention, in which lithium-based ferrite is replaced with Ho and Dy, has excellent power resistance characteristics, squareness ratio, coercive force, and magnetic loss, and is a magnetic material for microwave circuit elements. It is especially suitable as a ferrite for a latching phase shifter.

Further, the magnetic material of the present invention has various effects such as being able to be applied as a memory core of an electronic calculator by utilizing its excellent magnetic properties.

[Brief explanation of the drawing]

1 to 4 are graphs showing the characteristics of the ferrimagnetic material obtained in Example 1 of the present invention, FIG. 1 is a graph showing the resonance half width of spin waves, and FIG. 2 is a graph showing the squareness ratio. 3 is a graph showing the coercive force, and FIG. 4 is a graph showing the ferromagnetic resonance half width. 5 to 9 are graphs showing the characteristics of the ferrimagnetic materials obtained in Example 2 and Comparative Example of the present invention, FIG. 5 is a graph showing the minimum microwave magnetic field, and FIG. 6 is a graph showing the square shape. FIG. 8 is a graph showing the ferromagnetic resonance half width, FIG. 7 is a graph showing the coercive force, and FIG. 9 is a graph showing the magnetic f-hi curve.

Claims (1)

[Claims] 1f Lithium ferrite represented by the chemical formula LiO,5Fe2.504 is substituted with Mn alone or with Zn and Ti, and one or more of Ho and Dy is added to the substituted product.
．． A ferrimagnetic material for microwaves, characterized in that it contains 0.02 mol or less.