JP2007076964A - Magnetic material, and method for producing magnetic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic material having excellent temperature sensitivity, and to provide a method for producing the magnetic material. <P>SOLUTION: In Li-Zn-Cu ferrite expressed by the general formula of (1-z)[Li<SB>0.5x</SB>Zn<SB>1-x</SB>(Fe<SB>1-y</SB>Mn<SB>y</SB>)<SB>2+0.5x</SB>O<SB>4</SB>]+Cu(Fe<SB>1-y</SB>Mn<SB>y</SB>)<SB>2</SB>O<SB>4</SB>(0.35≤x≤0.90, 0≤y≤0.30, 0≤z≤0.60), it is controlled that the value of the compositional ratio x is reduced, and the values of y and z are increased. As a result, a magnetic substance (an Li-Zn-Cu ferrite material) having optional temperature sensitivity can be produced, and the control in the temperature variation of the initial permeability in the magnetic substance is made possible. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic material as a high-frequency ferrite material, a method for producing the magnetic material, and a temperature sensor and an LC oscillator using the magnetic material.

Ferrite is used in many electronic industries as a high permeability material for high frequencies. Ferrite is obtained by mixing iron oxide (Fe ₂ O ₂ ), which is a main component, and a metal compound such as manganese, magnesium, nickel, and zinc, and sintering at high temperature. Typical ferrites include Mn—Zn series, Ni—Zn series, Li series ferrite and the like. In addition, ferrite has a much higher electrical resistance than metal and is hardly affected by eddy currents, so it maintains stable magnetic properties up to a high frequency range.

  Furthermore, there is nickel-zinc-copper (Ni-Zn-Cu) ferrite as a low-temperature sintering type oxide magnetic material. However, as a high permeability material not containing Ni from the viewpoint of environmental regulations, Ni-- Li-Zn-Cu ferrite having magnetic properties equivalent to those of Zn-Cu ferrite is used (for example, see Patent Document 1).

JP 2004-153196 A

  Conventional high-frequency ferrite materials for inductors, such as Ni—Zn—Cu, have a small temperature change indicated by their magnetic permeability (initial magnetic permeability). Therefore, when a ferrite material is used as an element of a temperature sensor, it is difficult to apply the conventional high frequency ferrite material to a temperature sensor or the like. In addition, when temperature sensitive ferrite is used for sensors, most of them use Mn—Zn, Mn—Cu, and Ni—Zn based ferrites having a Curie point near room temperature, so a wide range of temperature detection is possible. There is a problem that you can not. Furthermore, there is a problem that these temperature-sensitive ferrites cannot be used at high frequencies.

  This invention is made | formed in view of the subject mentioned above, The place made into the objective is providing the manufacturing method of a magnetic material excellent in temperature sensitivity, and a magnetic material.

  Another object of the present invention is to provide a magnetic material capable of controlling temperature characteristics of magnetic characteristics, a method for manufacturing the magnetic material, and a temperature sensor and an LC oscillator to which the magnetic material is applied.

As a means for achieving this object and solving the above-mentioned problems, the present invention comprises, for example, the following configuration. In other words, the magnetic material of the present invention have the general formula _{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 It is characterized by being composed of Li—Zn—Cu ferrite having a composition ratio represented by O ₄ (0.35 ≦ x ≦ 0.90, 0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60).

Furthermore, as a means for solving the above-described problems, the present invention has the following configuration, for example. That is, a compound that is a magnetic material and includes at least lithium (Li), zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) oxide powder or carbonate powder the powder formula _{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 (0.35 ≦ x ≦ 0.90, 0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60).

For example, the lithium compound includes at least lithium carbonate (Li ₂ CO ₃ ) and lithium oxide (Li ₂ O), the zinc compound includes at least zinc oxide (ZnO), and the copper compound includes at least It consists of cupric oxide (CuO), the iron compound consists of at least ferric oxide (Fe ₂ O ₃ ), and the manganese compound contains at least manganese monoxide (MnO), manganese dioxide (MnO ₂ ), and three It is characterized by being composed of either dimanganese oxide (Mn ₂ O ₃ ) or trimanganese tetroxide (Mn ₃ O ₄ ).

For example, among the composition ratios x, y, and z, the value of x is relatively small, and the values of y and z are relatively large. For example, bismuth oxide (Bi ₂ O ₃ ) is further added in an amount of 0 to 5 weight percent.

As a means for solving the above-described problems, the present invention has the following configuration, for example. That is, a method for producing a magnetic material comprising at least lithium (Li), zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) oxide powder or carbonate powder the compound powder containing, formula _{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 ( 0.35 ≦ x ≦ 0.90, 0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60), and the mixed material at a temperature of 800 ° C. or higher. The method comprises a step of sintering, and a step of pulverizing the calcined powder obtained by the above-mentioned sintering into a Li—Zn—Cu ferrite powder having a predetermined particle size.

For example, in the manufacturing method of the magnetic material, in the mixing step, among the composition ratios x, y, and z, the value of x is relatively small, and the values of y and z are relatively large. Features. In addition, for example, the above-described method for producing a magnetic material further includes a step of adding 0 to 5 weight percent of bismuth oxide (Bi ₂ O ₃ ).

  As a means for solving the above-described problems, the present invention has the following configuration, for example. That is, a temperature sensor, wherein the magnetic material according to any one of the above inventions is used as a temperature detection element.

  Furthermore, as a means for solving the above-described problems, the present invention has the following configuration, for example. That is, an LC oscillator is characterized in that it is configured by combining an inductive element (L) made of a magnetic material according to any one of the above inventions and a capacitive element (C).

According to the present invention, it is possible to provide a magnetic material that is remarkably excellent in temperature sensitivity as compared with conventional ferrite materials, a method for producing the magnetic material, a temperature sensor using the magnetic material, and an LC oscillator. That is, among the composition ratios x, y, and z of Li—Zn—Cu ferrite, the value of x is relatively small, and the values of y and z are relatively large, so that the temperature change amount of the initial permeability can be increased. It can be adjusted to be larger. Further, by adding 0 to 5 weight percent of bismuth oxide (Bi ₂ O ₃ ) to Li—Zn—Cu ferrite, the temperature change amount of the magnetic permeability can be arbitrarily adjusted.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. First, the composition of Li—Zn—Cu ferrite powder, which is a temperature-sensitive ferrite material according to this embodiment, will be described. Here, in the Li—Zn—Cu ferrite represented by the following general formula (1) as the ferrite material, the temperature change amount of the initial permeability is controlled by adjusting the ranges of x, y, and z.

_{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 ... (1)

  FIG. 1 is a flowchart showing manufacturing steps of Li—Zn—Cu ferrite powder, which is a magnetic material according to this embodiment. In the present embodiment, as the first step for producing Li—Zn—Cu ferrite powder, the following materials are weighed in step S11 of FIG.

For example, lithium compounds such as lithium carbonate (Li ₂ CO ₃ ) or lithium oxide (Li ₂ O), zinc compounds such as zinc oxide (ZnO), cupric oxide (CuO) or cuprous oxide (Cu ₂ O) Copper compounds such as ferric oxide (Fe ₂ O ₃ ) or ferrous oxide (FeO) or triiron tetroxide (Fe ₃ O ₄ ), and trimanganese tetroxide (Mn ₃ O ₄₎ ) And the like as a composition ratio represented by x, y, z in the above formula (1), 0.1 ≦ x ≦ 0.9, 0 ≦ y ≦ 0.3, 0 ≦ z ≦ 0.6 Weigh so that

  In subsequent step S12, the composition is mixed. Specifically, the composition weighed in step S11 is placed in, for example, an iron dry mixer and mixed at a rotation speed of 30,000 rpm for 1 hour. In step S13, the material mixed in the above process is dried, and in subsequent step S14, the mixed powder obtained by drying is calcined. This calcination is performed, for example, at a temperature (T) of 800 ° C. for 3 hours (t). In addition, you may abbreviate | omit the drying process of step S13.

  In step S15, the calcined powder is put into a 0.7 L iron ball mill of iron ball media and, for example, pulverized in a mixed solvent of pure water and alcohol at a rotation speed of 130 rpm for about 13 hours. In step S16, the material pulverized as described above was dried to obtain a powder (Li—Zn—Cu ferrite powder) having an average particle diameter of 1.1 μm.

  Next, the manufacturing process of the Li—Zn—Cu ferrite sintered body in the present embodiment will be described. FIG. 2 is a flowchart showing a manufacturing process of the Li—Zn—Cu ferrite sintered body according to the present embodiment. In step S21 of FIG. 2, an aqueous solution of PVA 5 weight percent (wt%) + polypropylene glycol 5 weight percent (wt%) is added to the Li—Zn—Cu ferrite powder obtained by the process shown in FIG. To do.

  The subsequent step S23 is a step of forming the ferrite powder into a predetermined shape. In this forming step, the Li—Zn—Cu ferrite powder is formed into a toroidal core shape by a pressing pressure of 98 MPa, for example. In step S25, the molded product is degreased.

  In step S27, the molded product is fired. Specifically, the degreased molded product was heated at 200 ° C./hour, held at 800 to 970 ° C. for 2 hours, and then cooled at 200 ° C./hour to obtain a fired product. The size of the molded product obtained by this firing was about 15 mm for the outer shape, about 10 mm for the inner diameter, and about 4 mm for the thickness.

  Next, a manufacturing process of a multilayer ferrite component (multilayer chip inductor) using the Li—Zn—Cu ferrite powder according to the present embodiment will be described. FIG. 3 is a flowchart showing a manufacturing process of the multilayer chip inductor according to the present embodiment. In step S31 of FIG. 3, the Li—Zn—Cu ferrite powder produced by the above-described process is formed on a green sheet and cut into a predetermined size.

In addition, the composition of the ferrite powder at the time of manufacturing this multilayer chip inductor was set to x = 0.75, y = 0.10, z = 0.40 in the above-described formula (1). As will be described later, the amount of bismuth oxide (Bi ₂ O ₃ ), which is a sintering aid for controlling the crystal grain size, was set to 0 weight percent here.

  In step S32, vias are formed at predetermined positions on the green sheet, for example, by laser punching. This via is for connecting coil patterns between sheet layers to each other. In step S33, a coil pattern, internal electrodes, etc. are printed on the green sheet. For example, a coil pattern is drawn on a sheet with Ag paste using a screen printing method. Thereby, after lamination of the green sheets, a coil having a desired number of turns is formed in the chip inductor.

  In the subsequent step S34, the green sheets are temporarily laminated and then laminated by, for example, an isostatic press. In step S35, the stacked green sheets are cut into a predetermined chip size by, for example, dicing. And in step S36, after degreasing | defatting in the degreasing furnace with respect to the laminated product cut | disconnected by the predetermined size, it bakes in the predetermined | prescribed temperature range, for example in air | atmosphere.

  In subsequent step S37, external electrodes are formed on the fired product. For example, an Ag paste is applied by a dip method and baked to form an external electrode, thereby obtaining a multilayer chip inductor. Here, the multilayer chip inductor manufactured in this way and a commercially available capacitor were mounted on a parallel circuit board to create a parallel LC resonator.

  About what shape | molded the Li-Zn-Cu ferrite sintered compact, the temperature characteristic of the initial permeability is an impedance analyzer (measurement frequency: 10 MHz or 1 MHz) and a thermostat (measurement temperature range: -35-125 degreeC). It measured using. Moreover, the temperature characteristics of the manufactured multilayer chip inductor and the produced LC resonator were measured in the measurement frequency range of 1 MHz to 1.8 GHz using the impedance analyzer and the thermostatic bath.

  Next, the characteristics of the Li—Zn—Cu ferrite sintered body according to this embodiment will be described in detail. 4 to 6 show a sample of the Li—Zn—Cu ferrite sintered body according to the present embodiment, and any two of the composition ratios indicated by x, y, and z in the above formula (1). The electrical characteristics (temperature change of initial permeability) when the composition ratio is fixed and the remaining composition ratio is changed are shown.

  FIG. 4 shows that in the Li—Zn—Cu ferrite sintered body, y = 0.10, z for each of the composition ratios of y and z among the composition ratios indicated by x, y, z in the above formula (1). = 0.40, and the change in temperature of the initial permeability of the sample in which the composition ratio of x is changed in the range of 0.35 ≦ x ≦ 0.9. In the following description, the amount of change in the initial permeability of each sample with respect to the values of the composition ratio x, y, z in the above equation (1) is represented by the symbols ○, Δ, □, ●, ▲, It is shown corresponding to {circle around (3)} and is normalized with a temperature of 22 ° C. as a reference.

  As can be seen from FIG. 4, the smaller the value of x, the greater the amount of change (%) in the initial permeability in the measurement range. As a result, regarding the Li—Zn—Cu ferrite sintered body according to the present embodiment, even if the combination of the y and z compositions is different, if x decreases, the temperature change in the initial permeability increases. I can analogize. Moreover, when the value of x is further reduced, it can be considered that the change in the initial permeability maintains the increasing tendency.

  FIG. 5 shows that in the Li—Zn—Cu ferrite sintered body, among the composition ratios indicated by x, y, and z in the above formula (1), x = 0.75, z = It shows the temperature change of the initial permeability of the sample fixed at 0.40 and changing the composition ratio of y in the range of 0 ≦ y ≦ 0.3. FIG. 5 shows that the larger the value of y, the larger the amount of change (%) in the initial permeability of the Li—Zn—Cu ferrite sintered body in the measurement range.

  From this result, it can be inferred that even if the combination of the composition of x and z is different, the larger the y, the greater the temperature change of the initial permeability of the Li—Zn—Cu ferrite sintered body. Further, when the value of y is further increased, it is considered that the same tendency of increasing the initial permeability as described above is maintained.

  FIG. 6 shows that in the Li—Zn—Cu ferrite sintered body, among the composition ratios indicated by x, y, z in the above formula (1), x = 0.75, y = This is a change in temperature of the initial permeability of a sample fixed at 0.10 and changing the composition ratio of z in the range of 0 ≦ z ≦ 0.6. From FIG. 6, it can be seen that the larger the z is, the larger the amount of change (%) in the initial permeability of the Li—Zn—Cu ferrite sintered body in the measurement range.

  From this, it can be inferred that even if the combination of x and y is different, if z is large, the temperature change of the initial permeability of the Li—Zn—Cu ferrite sintered body becomes large. Further, when the value of z is further increased, it can be considered that the change in the initial permeability maintains an increasing tendency as described above.

  Eventually, the Li—Zn—Cu ferrite sintered body according to the present embodiment is 0.35 ≦ x ≦ 0.90, 0 ≦ y ≦ with respect to the composition ratio x, y, z of the above-described formula (1). By adjusting and mixing in the range represented by 0.30, 0 ≦ z ≦ 0.60, as shown in FIGS. 4 to 6, the temperature change amount of the initial permeability is controlled in the range of 70 to 170%. It becomes possible.

Next, the relationship between the additive amount of Bi ₂ O ₃ that is a sintering aid for controlling the crystal grain size in the Li—Zn—Cu ferrite sintered body according to the present embodiment and the initial permeability will be described. To do. FIG. 7 shows that in the Li—Zn—Cu ferrite sintered body, x = 0.75, y = 0.10, and z = 0.10 with respect to the composition ratio x, y, z in the above formula (1). The sample shows the change (%) in the initial permeability when 0 to 5 weight percent (wt%) of Bi ₂ O ₃ as a sintering aid is added. FIG. 8 shows the change in density (bulk density [g / cm ³ ]) relative to the amount of Bi ₂ O ₃ added (0 to 5 weight percent) for the sample shown in FIG.

FIG. 8 shows that the bulk density is almost constant with respect to the amount of Bi ₂ O ₃ added. Therefore, from the results shown in FIG. 7, the Li—Zn—Cu ferrite sintered body to which Bi ₂ O ₃ is added in an amount of 0 to 5 percent by weight is added with Bi ₂ O ₃ even though its density is substantially constant. It can be seen that the greater the amount, the greater the amount of change in initial permeability in the measurement range.

Therefore, when the cross section of the Li—Zn—Cu ferrite sintered body according to the present embodiment is observed with an SEM (scanning electron microscope), the larger the amount of Bi ₂ O ₃ added, the larger the particle size. Was confirmed. That is, as the amount of the sintering aid (Bi ₂ O ₃ ) added is increased, the grain growth of the ferrite polycrystalline body is promoted, and the temperature change of the initial permeability within the measurement range increases. In other words, the temperature change of the initial permeability can be arbitrarily controlled by adjusting the addition amount of Bi ₂ O ₃ to control the crystal grain size.

From the above results, when it is desired to increase the temperature change of the initial permeability of the Li—Zn—Cu ferrite sintered body, x is small in the composition ratios x, y, and z in the above formula (1), and y and It can be seen that z should be increased and the amount of Bi ₂ O ₃ added should be increased. Therefore, the Li—Zn—Cu ferrite in which the composition ratios x, y, z and the addition amount of Bi ₂ O ₃ are arbitrarily changed can be applied to a temperature sensor having an arbitrary sensitivity (temperature sensitivity). .

FIG. 9 shows a multilayer chip inductor manufactured by the above-described process (see FIG. 3), that is, in the above equation (1), x = 0.75, y = 0.10, z = 0.40, Bi ₂ shows the relationship between the inductance and temperature at 10 MHz of an inductor using Li—Zn—Cu ferrite in which the amount of ₂ O ₃ added is 0 weight percent.

  As can be seen from the temperature characteristics shown in FIG. 9, in the case of room temperature reference, the total change amount of the measured temperature range of this inductor is about 160%. Further, the rate of change in inductance is a monotonous change proportional to the square of the temperature. This means that the Li—Zn—Cu ferrite according to the present embodiment has sufficient use as a temperature sensor element.

  FIG. 10 shows the relationship between the resonant frequency and temperature of a parallel LC resonator composed of the multilayer chip inductor manufactured in the process shown in FIG. 3 and a commercially available capacitor. As shown in FIG. 10, the resonance frequency of the LC resonator by the inductor using the Li—Zn—Cu ferrite according to the present embodiment changes linearly with respect to the temperature. Therefore, the LC resonator can be used in a temperature variable LC resonator, that is, a resonator including an oscillation circuit whose frequency changes linearly with respect to a change in temperature.

  On the other hand, FIG. 11 shows the relationship between impedance and temperature at 14 MHz of the parallel LC resonator described above. From the temperature change of the impedance shown in FIG. 11, when the total amount of change in the impedance was examined with reference to the lowest temperature measurement point in the measurement temperature range, it was 1200%.

  Therefore, when a constant-frequency high-frequency signal (14 MHz in this case) is input to this parallel LC resonator, the output of this LC resonator becomes an amplitude-modulated waveform signal carried by the high-frequency carrier signal, and the amplitude change is It becomes a value according to the above-mentioned impedance temperature change of 1200%. As a result, the inductor using the Li—Zn—Cu ferrite according to the present embodiment can be applied as a high frequency carrier type temperature sensor element.

As described above, according to the embodiment, the general formula _{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1- _y Mn _y ) ₂ O ₄ (0.35 ≦ x ≦ 0.90, 0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60) By reducing y and adjusting y and z large, a magnetic material (Li—Zn—Cu ferrite material) having any temperature sensitivity can be manufactured.

Further, by arbitrarily changing the amount of Bi ₂ O ₃ added to the Li—Zn—Cu ferrite, the Li—Zn—Cu ferrite material can be given any temperature sensitivity. Therefore, the magnetic material according to the present embodiment can be applied to a temperature sensor as a temperature sensor element, and can also be applied to an LC resonator using an inductor using such a magnetic material.

It is a flowchart which shows the manufacturing process of the Li-Zn-Cu ferrite powder which concerns on the embodiment of this invention. It is a flowchart which shows the manufacturing process of the Li-Zn-Cu ferrite sintered compact which concerns on the embodiment. It is a flowchart which shows the manufacturing process of the multilayer chip inductor which concerns on the example of an embodiment. It is a figure which shows the temperature change amount of the initial magnetic permeability of the sample which fixed the composition ratio of y and z among composition ratio x, y, z, and changed the composition ratio of x. It is a figure which shows the temperature variation of the initial magnetic permeability of the sample which fixed the composition ratio of x and z among composition ratio x, y, z, and changed the composition ratio of y. It is a figure which shows the temperature variation of the initial magnetic permeability of the sample which fixed the composition ratio of x and y among composition ratio x, y, and z, and changed the composition ratio of z. The Bi ₂ O ₃ is a graph showing changes in initial permeability of adding 0-5% by weight. The addition amount of Bi ₂ O ₃ is a diagram showing a variation of the density with respect to a change in (0-5 wt%). It is a figure which shows the relationship between the inductance in 10 MHz of the multilayer chip inductor using Li-Zn-Cu ferrite, and temperature. It is a figure which shows the relationship between the resonant frequency and temperature of the parallel LC resonator which consists of a multilayer chip inductor and a capacitor. It is a figure which shows the relationship between the impedance in 14 MHz of a parallel LC resonator using a multilayer chip inductor, and temperature.

Claims (10)

Formula _{(1-z) [Li 0.5x} Zn 1-x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 (0.35 ≦ x ≦ 0 .90, 0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60). A magnetic material comprising Li—Zn—Cu ferrite having a composition ratio represented by: A compound powder containing at least lithium (Li), zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) oxide powder or carbonate powder is represented by the general formula (1). _{-z) [Li 0.5x Zn 1-} x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 (0.35 ≦ x ≦ 0.90,0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60). A magnetic material obtained by mixing at a composition ratio represented by: The lithium compound is composed of at least lithium carbonate (Li ₂ CO ₃ ) or lithium oxide (Li ₂ O), the zinc compound is composed of at least zinc oxide (ZnO), and the copper compound is composed of at least oxidized oxide. The iron compound is made of at least ferric oxide (Fe ₂ O ₃ ), and the manganese compound is made of at least manganese monoxide (MnO), manganese dioxide (MnO ₂ ) and ditrioxide. The magnetic material according to claim 2, comprising either manganese (Mn ₂ O ₃ ) or trimanganese tetroxide (Mn ₃ O ₄ ). 4. The magnetic material according to claim 1, wherein, among the composition ratios x, y, and z, the value of x is relatively small and the values of y and z are relatively large. . The magnetic material according to claim 4, further comprising 0 to 5 weight percent of bismuth oxide (Bi ₂ O ₃ ) added. A compound powder containing at least lithium (Li), zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) oxide powder or carbonate powder is represented by the general formula (1). _{-z) [Li 0.5x Zn 1-} x (Fe 1-y Mn y) 2 + 0.5x O 4] + Cu (Fe 1-y Mn y) 2 O 4 (0.35 ≦ x ≦ 0.90,0 ≦ y ≦ 0.30, 0 ≦ z ≦ 0.60), and mixing with a composition ratio represented by
Sintering the mixed material at a temperature of 800 ° C. or higher;
And crushing the sintered powder obtained by the sintering to obtain a Li—Zn—Cu ferrite powder having a predetermined particle diameter. 7. The magnetic material according to claim 6, wherein in the mixing step, among the composition ratios x, y, and z, the value of x is relatively small, and the values of y and z are relatively large. Production method. The method of manufacturing a magnetic material according to claim 7, further comprising the step of adding 0 to 5 weight percent of bismuth oxide (Bi ₂ O ₃ ). 6. A temperature sensor using the magnetic material according to claim 1 as a temperature detection element. An LC oscillator comprising a combination of the inductive element (L) made of the magnetic material according to claim 1 and a capacitive element (C).

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