JP4508626B2 - Mn-Co-Zn ferrite - Google Patents
Mn-Co-Zn ferrite Download PDFInfo
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- JP4508626B2 JP4508626B2 JP2003419143A JP2003419143A JP4508626B2 JP 4508626 B2 JP4508626 B2 JP 4508626B2 JP 2003419143 A JP2003419143 A JP 2003419143A JP 2003419143 A JP2003419143 A JP 2003419143A JP 4508626 B2 JP4508626 B2 JP 4508626B2
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- 229910000859 α-Fe Inorganic materials 0.000 title claims description 61
- 229910020521 Co—Zn Inorganic materials 0.000 title claims description 21
- 239000000654 additive Substances 0.000 claims description 18
- 229910052796 boron Inorganic materials 0.000 claims description 14
- 229910052801 chlorine Inorganic materials 0.000 claims description 14
- 229910052698 phosphorus Inorganic materials 0.000 claims description 14
- 229910052717 sulfur Inorganic materials 0.000 claims description 14
- 230000000996 additive effect Effects 0.000 claims description 12
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 11
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 claims description 8
- 230000004907 flux Effects 0.000 description 36
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 33
- 230000002159 abnormal effect Effects 0.000 description 19
- 239000000203 mixture Substances 0.000 description 16
- 230000007423 decrease Effects 0.000 description 14
- 238000010304 firing Methods 0.000 description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 239000012535 impurity Substances 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 10
- 230000000694 effects Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 239000011812 mixed powder Substances 0.000 description 10
- 229910052760 oxygen Inorganic materials 0.000 description 10
- 239000001301 oxygen Substances 0.000 description 10
- 239000002994 raw material Substances 0.000 description 9
- 239000000843 powder Substances 0.000 description 8
- 239000004372 Polyvinyl alcohol Substances 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 229920002451 polyvinyl alcohol Polymers 0.000 description 7
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 229910018605 Ni—Zn Inorganic materials 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 5
- 230000035699 permeability Effects 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 230000002411 adverse Effects 0.000 description 3
- 238000001354 calcination Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 3
- 238000004663 powder metallurgy Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- UCNNJGDEJXIUCC-UHFFFAOYSA-L hydroxy(oxo)iron;iron Chemical compound [Fe].O[Fe]=O.O[Fe]=O UCNNJGDEJXIUCC-UHFFFAOYSA-L 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
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- Compounds Of Iron (AREA)
- Magnetic Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Soft Magnetic Materials (AREA)
Description
本発明は、比抵抗が高く、かつ残留磁束密度に対する飽和磁束密度の比（残留磁束密度／飽和磁束密度）である角形比の小さいMn−Co−Zn系フェライトに関するものである。 The present invention relates to an Mn—Co—Zn ferrite having a high specific resistance and a small squareness ratio which is a ratio of a saturation magnetic flux density to a residual magnetic flux density (residual magnetic flux density / saturation magnetic flux density).
軟磁性酸化物磁性材料の代表的な例として、Mn−Znフェライトが挙げられる。従来のMn−Znフェライトは、正の磁気異方性を持つFe2+を約２mass％以上含み、これを負の磁気異方性を持つFe3+およびMn2+と相殺させることにより、高い初透磁率や低い損失を得ている。 A typical example of the soft magnetic oxide magnetic material is Mn-Zn ferrite. Conventional Mn-Zn ferrite contains about 2 mass% or more of Fe 2+ with positive magnetic anisotropy, which is high by offsetting it with Fe 3+ and Mn 2+ with negative magnetic anisotropy. Initial permeability and low loss are obtained.
しかしFe2+量が多くなると、Fe3＋およびFe2+間での電子の授受が起こりやすくなり、その結果として比抵抗が非常に小さな、0.1Ω・mオーダーにまで低下してしまうという欠点がある。そのために、使用する周波数領域が高くなると、フェライト内を流れる渦電流による損失が急増することになる。すなわち、Mn−Znフェライトは、高周波領域において初透磁率が大きく低下し、損失も増大するため、耐用周波数は数百kHz程度が限界とされているのである。 However, when the amount of Fe 2+ increases, electrons are easily exchanged between Fe 3+ and Fe 2+, and as a result, the specific resistance is very small, and it is reduced to the order of 0.1 Ω · m. is there. Therefore, when the frequency region to be used becomes high, the loss due to the eddy current flowing in the ferrite increases rapidly. In other words, Mn-Zn ferrite has a significant decrease in initial permeability and an increase in loss in a high frequency region, so that the serviceable frequency is limited to about several hundred kHz.
かような背景から、MHzオーダーの周波数領域で使用されるフェライトは、Ni−Znフェライトが主となっている。なぜなら、Ni−ZnフェライトはMn−Znフェライトの約1万倍に達する、105（Ω・m）以上の非常に高い比抵抗を持つため、渦電流損失による影響が無視でき、高周波領域でも初透磁率、低損失という特性が失われにくいからである。 From such a background, the Ni-Zn ferrite is mainly used as the ferrite used in the frequency range of MHz order. This is because Ni-Zn ferrite has an extremely high specific resistance of 10 5 (Ω · m) or more, which is about 10,000 times that of Mn-Zn ferrite. This is because the characteristics of magnetic permeability and low loss are not easily lost.
しかし、Ni−Znフェライトには大きな問題点がある。それは、NiはMnよりも負の磁気異方性エネルギーが大きく、また正の磁気異方性を持つFe2+をほとんど含まないことから、角形比が大きくなることである。ここで、角形比とは、残留磁束密度を飽和磁束密度で除したものであり、この値が大きいと、一旦外部から磁界が印加された後に、初透磁率が大きく低下し、同時に損失の増大を招くことになる。すなわち、角形比が大きいことは、軟磁性材料としての特性を非常に損ねる原因となる。 However, Ni-Zn ferrite has a big problem. This is because Ni has a larger negative magnetic anisotropy energy than Mn and contains almost no Fe 2+ having a positive magnetic anisotropy, so that the squareness ratio is increased. Here, the squareness ratio is a value obtained by dividing the residual magnetic flux density by the saturation magnetic flux density. If this value is large, the initial permeability is greatly reduced after the magnetic field is once applied from the outside, and the loss is increased at the same time. Will be invited. That is, a large squareness ratio causes a great loss of the properties as a soft magnetic material.
Ni−Znフェライト以外に比抵抗の大きいフェライトを得る方法として、Mn−Znフェライト中に含まれるFe2+量を減らすことで比抵抗を上昇させる、という技術がある。例えば、Fe2O3成分を50mol％未満としてFe2+含有量を減らし比抵抗を高めた、Mn−Znフェライトについて、特許文献１〜３に記載されている。
しかしながら、これらMn−ZnフェライトもNi−Znフェライトと同様に、負の磁気異方性を持つイオンのみから成るため、角形比の低減という課題は全く解決されていない。
As a method for obtaining ferrite having a large specific resistance other than Ni-Zn ferrite, there is a technique of increasing the specific resistance by reducing the amount of Fe 2+ contained in the Mn-Zn ferrite. For example, Patent Documents 1 to 3 describe Mn—Zn ferrite in which Fe 2 O 3 component is less than 50 mol% and Fe 2+ content is reduced to increase specific resistance.
However, since these Mn-Zn ferrites are also composed of only ions having negative magnetic anisotropy, like Ni-Zn ferrites, the problem of reducing the squareness ratio has not been solved at all.
一方、Fe2＋以外の正の磁気異方性を持つCo2＋をMn−Znフェライトに添加する技術が、特許文献４〜６において提案されている。
しかし、これらの文献中には、角形比はおろか、飽和磁束密度および残留磁束密度に関する記述は全くない。しかも、実際に製造した場合に、比抵抗の低下並びにその他磁気特性の劣化をまねくことがあり、従って角形比の低いMn−Znフェライトを安定して得ることが困難であった。
On the other hand, Patent Documents 4 to 6 propose techniques for adding Co 2+ having positive magnetic anisotropy other than Fe 2+ to Mn-Zn ferrite.
However, these documents do not describe the saturation magnetic flux density and the residual magnetic flux density as well as the squareness ratio. In addition, when actually manufactured, it may lead to a decrease in specific resistance and deterioration of other magnetic properties, and thus it is difficult to stably obtain Mn-Zn ferrite having a low squareness ratio.
さらに、実際に製造する際に、コストおよび製造効率の面に問題を残すものである。すなわち、特許文献４および５に記載された実施例は、非常に低い酸素濃度雰囲気下で焼成が行われるために、
ａ）焼成炉の厳密なシールおよび雰囲気制御
ｂ）（工業用窒素は最低でも１〜20体積ppmの酸素を含むため）純窒素の使用
が要求される。これらの規制は、工業化を考えた際に、製造効率およびコストの両面において問題となる。
Furthermore, when actually manufacturing, problems remain in terms of cost and manufacturing efficiency. That is, the examples described in Patent Documents 4 and 5 are fired in a very low oxygen concentration atmosphere.
a) Strict sealing of firing furnace and atmosphere control b) The use of pure nitrogen is required (since industrial nitrogen contains at least 1-20 ppm by volume of oxygen). These regulations are problematic in terms of both production efficiency and cost when considering industrialization.
一方、特許文献６の実施例には、ブリッジマン法による単結晶育成についてのみが記載されている。この手法は、従来の粉末冶金法でフェライトを製造する場合と比較すると、工業化の際の製造効率およびコストが、当然ながら大きく劣ることは否めない。
本発明は、上記の問題を有利に解決するものであり、正の磁気異方性エネルギーを持つCoOの添加により、比抵抗の低下並びにその他磁気特性の劣化をまねくことなしに角形比の大幅な低下を実現した、Mn−Co−Zn系フェライトを提供しようとするものである。 The present invention advantageously solves the above problem, and by adding CoO having a positive magnetic anisotropy energy, the squareness ratio is greatly increased without lowering the specific resistance and other magnetic characteristics. An object of the present invention is to provide an Mn-Co-Zn-based ferrite that realizes the reduction.
さて、発明者らは、CoOの添加により正負の磁気異方性を相殺したMn−Co−Zn系フェライトにおいて、大きな比抵抗や優れた磁気特性が安定して得られない原因について検討したところ、フェライトの製造過程における異常粒成長が関係していることを見出した。すなわち、異常粒成長とは、何らかの原因により局部的に粒成長のバランスが崩れた際に起こる、特に粉末冶金法を用いた製造時にしばしば見られる現象である。この異常成長粒内には、不純物や格子欠陥等の磁壁の移動を大きく妨げる物質が混入するため、残留磁束密度が上昇し、その結果角形比が上昇することになる。同時に、結晶粒界形成が不十分になることから、比抵抗は低下し、その他の磁気特性および強度についても大きく劣化するのである。 Now, the inventors examined the reason why large specific resistance and excellent magnetic properties could not be stably obtained in the Mn-Co-Zn based ferrite in which the positive and negative magnetic anisotropies were offset by the addition of CoO. We found that abnormal grain growth in the ferrite manufacturing process is related. In other words, abnormal grain growth is a phenomenon that occurs when the grain growth balance is locally lost for some reason, and is often observed particularly during production using powder metallurgy. In this abnormally grown grain, substances that greatly impede the movement of the domain wall, such as impurities and lattice defects, are mixed, so that the residual magnetic flux density is increased, and as a result, the squareness ratio is increased. At the same time, since the formation of crystal grain boundaries becomes insufficient, the specific resistance is lowered, and the other magnetic properties and strength are greatly deteriorated.
さらに、発明者らは、フェライトの原料、中でも主原料であるFe2O3の大半が製鉄の際に発生するスケールに依存していることに着目し、スケール由来のFe2O3原料と上記異常成長粒との関連を調査した。その結果、鉄鋼（スケール）中に不可避に混入するＰ、Ｂ、ＳおよびClという不純物が含有された、フェライトは、異常粒成長を誘発し、結果として軟磁性フェライトの磁気特性や比抵抗等の諸特性に対して重大な悪影響を及ばすことが、新たに判明した。 Furthermore, the inventors pay attention to the fact that most of the raw material of ferrite, especially the main raw material Fe 2 O 3 depends on the scale generated during iron making, and the scale-derived Fe 2 O 3 raw material and the above-mentioned The relationship with abnormally grown grains was investigated. As a result, ferrite containing P, B, S and Cl impurities inevitably mixed in steel (scale) induces abnormal grain growth, resulting in the magnetic properties and resistivity of soft magnetic ferrite. It has been newly found that it has a serious adverse effect on various properties.
すなわち、上記した特許文献４〜６に記載された技術では、かような不純物についての規制は何ら行われていないため、これら文献に開示の技術内容に従うだけでは、同文献に記載された望ましい特性を持つMn−Co−Zn系フェライトの製造は、実際上困難であったのである。 That is, in the techniques described in Patent Documents 4 to 6 described above, since there is no restriction on such impurities, the desired characteristics described in the same document are merely obtained according to the technical contents disclosed in these documents. Production of Mn—Co—Zn based ferrite having a Pt was actually difficult.
本発明は、上記の知見に立脚するものである。
すなわち、本発明の要旨構成は次のとおりである。
（１）Fe2O3：45.0mol％以上50.0mol％未満、
CoO：0.5mol％以上4.0mol％以下、
ZnO：15.5mol％以上24.0mol％以下および
MnO：残部
を基本成分とし、
フェライト中に含まれるＰ、Ｂ、ＳおよびClが、
Ｐ：50massppm未満、
Ｂ：20massppm未満、
Ｓ：30massppm未満および
Cl：50massppm未満
であることを特徴とするMn−Co−Zn系フェライト。
The present invention is based on the above findings.
That is, the gist configuration of the present invention is as follows.
(1) Fe 2 O 3 : 45.0 mol% or more and less than 50.0 mol%,
CoO: 0.5 mol% or more and 4.0 mol% or less,
ZnO: 15.5 mol% to 24.0 mol% and
MnO: The balance is the basic component,
P, B, S and Cl contained in the ferrite are
P: less than 50 massppm,
B: Less than 20 massppm
S: less than 30 massppm and
Cl: Mn-Co-Zn ferrite characterized by being less than 50 massppm.
（２）前記フェライト中に、添加物としてさらに
CaO：0.005〜0.200mass％および
SiO2：0.001〜0.050mass％
のうちから選んだ１種または２種を含有する上記（１）に記載のMn−Co−Zn系フェライト。
(2) In the ferrite, as an additive
CaO: 0.005-0.200 mass% and
SiO 2 : 0.001 to 0.050 mass%
The Mn-Co-Zn ferrite according to (1) above, which contains one or two selected from the above.
（３）前記フェライト中に、添加物としてさらに
ZrO2：0.005〜0.100mass％、
Ta2O5：0.005〜0.100mass％、
HfO2：0.005〜0.100mass％および
Nb2O5：0.005〜0.100mass％
のうちから選んだ１種または２種以上を含有する上記（１）または（２）に記載のMn−Co−Zn系フェライト。
(3) In the ferrite, as an additive
ZrO 2 : 0.005 to 0.100 mass%,
Ta 2 O 5 : 0.005 to 0.100 mass%,
HfO 2 : 0.005 to 0.100 mass% and
Nb 2 O 5 : 0.005 to 0.100 mass%
The Mn-Co-Zn ferrite according to (1) or (2) above, which contains one or more selected from among the above.
（４）前記フェライト中に、添加物としてさらに
V2O5：0.001〜0.100mass％、
Bi2O3：0.001〜0.100mass％、
In2O3：0.001〜0.100mass％、
MoO3：0.001〜0.100mass％および
WO3：0.001〜0.100mass％
のうちから選んだ１種または２種以上を含有する上記（１）、（２）または（３）に記載のMn−Co−Zn系フェライト。
(4) In the ferrite, further as an additive
V 2 O 5 : 0.001 to 0.100 mass%,
Bi 2 O 3 : 0.001 to 0.100 mass%,
In 2 O 3 : 0.001 to 0.100 mass%,
MoO 3 : 0.001 to 0.100 mass% and
WO 3: 0.001~0.100mass%
The Mn-Co-Zn ferrite according to the above (1), (2) or (3), which contains one or more selected from among the above.
本発明のMn−Co−Zn系フェライトは、上記の構成によって、従来実現されなかった、キュリー温度100℃以上で、しかも室温（23℃）における比抵抗が30Ω・m以上かつ角形比が0.35以下という、優れた特性を有するものとなる。 The Mn—Co—Zn ferrite of the present invention has a Curie temperature of 100 ° C. or higher, a specific resistance at room temperature (23 ° C.) of 30 Ω · m or higher, and a squareness ratio of 0.35 or lower, which has not been realized by the above configuration. That is, it has excellent characteristics.
本発明によれば、キュリー温度を100℃以上に保持したまま、室温（23℃）での比抵抗を高くかつ角形比を低くした、Mn−Co−Zn系フェライトを提供することができる。 According to the present invention, it is possible to provide an Mn—Co—Zn ferrite having a high specific resistance at room temperature (23 ° C.) and a low squareness ratio while maintaining the Curie temperature at 100 ° C. or higher.
このフェライトに、CaO、SiO2の１種または２種を適量添加して粒界偏析の効果を利用することによって、さらなる比抵抗の上昇を、またZrO2，Ta2O5，HfO2およびNb2O5の１種または２種以上を適量添加して結晶粒径を抑えることによって、さらなる角形比の低下を、そしてV2O5，Bi2O3，MoO3およびWO3の１種または２種以上を適量添加し、焼結密度を上昇させて飽和磁束密度を上昇させることによって、さらなる角形比の低下を、それぞれ達成することができる。さらに、これらを組み合わせて添加することにより、上記の効果を併せた効果が得られる。 By adding an appropriate amount of one or two of CaO and SiO 2 to this ferrite and utilizing the effect of grain boundary segregation, the resistivity increases further, and ZrO 2 , Ta 2 O 5 , HfO 2 and Nb By further adding one or more of 2 O 5 in an appropriate amount to suppress the crystal grain size, further reduction of the squareness ratio and one of V 2 O 5 , Bi 2 O 3 , MoO 3 and WO 3 or A further reduction in the squareness ratio can be achieved by adding an appropriate amount of two or more and increasing the sintered density to increase the saturation magnetic flux density. Furthermore, the effect which combined said effect is acquired by adding combining these.
また、本発明のフェライトは、不純物量に制限を加え、異常粒成長の発生や、雰囲気の変動に伴う特性劣化を抑制している。そのため、その製造時に粉末冶金的な手法を用いることができ、さらに焼成の際の冷却時に、例えば酸素を１〜20体積ppm含む工業用の窒素を用いることが可能であるから、従来に比べ大幅な製造コストの削減および異常粒成長を抑制した、安定した製造が実現される。 Further, the ferrite of the present invention limits the amount of impurities and suppresses the occurrence of abnormal grain growth and the deterioration of characteristics due to the change in atmosphere. Therefore, it is possible to use a powder metallurgy method during the production, and furthermore, it is possible to use, for example, industrial nitrogen containing 1 to 20 ppm by volume of oxygen at the time of cooling during firing. Stable production with reduced production costs and abnormal grain growth is realized.
以下、本発明を具体的に説明する。
まず、本発明において、基本成分を上記の範囲に限定した理由について説明する。なお、本発明における基本成分組成は、含まれるFeおよびMnをすべてFe2O3およびMnOとして換算した場合のものである。
The present invention will be specifically described below.
First, the reason why the basic component is limited to the above range in the present invention will be described. In addition, the basic component composition in the present invention is a case where all Fe and Mn contained are converted as Fe 2 O 3 and MnO.
Fe2O3：45.0mol％以上50.0mol％未満
基本成分のうち、Fe2O3は過剰に含まれた場合Fe2+量が増加し、それによりMn−Zn系フェライトの比抵抗が低下して高周波領域での磁気特性に悪影響を及ぼす。これを避けるために、Fe2O3量を50.0mol％未満に抑える必要がある。しかしながら、少なすぎると、今度は角形比の上昇およびキュリー温度の低下を招くため、最低でも45.0mol％は含有することとした。
Fe 2 O 3 : 45.0 mol% or more and less than 50.0 mol% Among the basic components, Fe 2 O 3 content increases when Fe 2 O 3 is contained excessively, which decreases the resistivity of Mn-Zn ferrite. Adversely affects the magnetic properties in the high frequency range. In order to avoid this, the amount of Fe 2 O 3 needs to be suppressed to less than 50.0 mol%. However, if the amount is too small, this causes an increase in the squareness ratio and a decrease in the Curie temperature. Therefore, the minimum content is 45.0 mol%.
CoO：0.5mol％以上4.0mol％以下
Co2+は、正の磁気異方性エネルギーをもつイオンであり、従ってCoOを適正量で添加すれば、磁気異方性エネルギーの総和の絶対値が低下する結果、角形比の低下が実現される。そのためには、CoOを0.5mol％以上で添加することが必須である。しかし、多量に添加すると、比抵抗の低下および異常粒成長の誘発をまねき、また磁気異方性エネルギーの総和が正に著しく傾くことから、逆に角形比の上昇をまねく。この事態を防ぐためには、CoOを最大4.0mol％の添加にとどめるものとする。
CoO: 0.5mol% to 4.0mol%
Co 2+ is an ion having a positive magnetic anisotropy energy. Therefore, if CoO is added in an appropriate amount, the absolute value of the sum of the magnetic anisotropy energy decreases, resulting in a reduction in the squareness ratio. The For that purpose, it is essential to add CoO at 0.5 mol% or more. However, when added in a large amount, the resistivity decreases and abnormal grain growth is induced, and the sum of the magnetic anisotropy energy is significantly inclined to the positive side, so that the squareness ratio is increased. To prevent this situation, CoO is limited to a maximum addition of 4.0 mol%.
ZnO：15.5mol％以上24.0mol％以下
ZnOは、非磁性であるため、その添加により、負の磁気異方性を持つFe２＋，Mn２＋が減少することになる。その結果、全体の負の磁気異方性エネルギーが低減されることから角形比の低下に有効な成分である。そこで、最低でも15.5mol％は含有するものとする。しかし、含有量が適正な値より多い場合には、キュリー温度の低下を招き、実用上問題がある。そのため、上限を24.0mol％とする。
ZnO: 15.5mol% to 24.0mol%
Since ZnO is nonmagnetic, addition of Fe 2+ and Mn 2+ with negative magnetic anisotropy decreases. As a result, since the overall negative magnetic anisotropy energy is reduced, it is an effective component for reducing the squareness ratio. Therefore, the minimum content is 15.5 mol%. However, if the content is higher than the appropriate value, the Curie temperature is lowered, which causes a practical problem. Therefore, the upper limit is 24.0 mol%.
MnO：残部
本発明はMn−Co−Znフェライトであり、主成分組成における残部はMnＯである必要がある。その理由は、MnＯを含有することにより、高飽和磁束密度、低損失および高透磁率の良好な磁気特性が得られるためである。
MnO: balance The present invention is Mn-Co-Zn ferrite, and the balance in the main component composition needs to be MnO. The reason is that by containing MnO, good magnetic properties such as high saturation magnetic flux density, low loss, and high magnetic permeability can be obtained.
Ｐ：50massppm未満、Ｂ：20massppm未満、Ｓ：30massppm未満およびCl：50massppm未満
Ｐ，Ｂ，ＳおよびClは、いずれも原料酸化鉄中に不可避に含まれる成分である。これらの含有がごく微量であれば問題はないが、ある一定量以上含まれる場合にはフェライトの異常粒成長を誘発し、得られるフェライトの諸特性に重大な悪影響を及ぼす。上記換算後のFe203含有量が50mol％未満の組成になり、さらにCoＯを含有するフェライトは、同含有量が50mol％以上のものに比べて、結晶の粒成長が進行しやすく、そのため異常粒成長が発生しやすくなる。従って、角形比を0.35以下とするためには、特にＰ、Ｂ、ＳおよびClの含有量をそれぞれ50，20，30および50ppm未満に制限する必要がある。
P: less than 50 massppm, B: less than 20 massppm, S: less than 30 massppm and Cl: less than 50 massppm P, B, S and Cl are all components inevitably contained in the raw iron oxide. If these contents are very small, there is no problem, but if they are contained in a certain amount or more, abnormal grain growth of the ferrite is induced, and the various properties of the obtained ferrite are seriously adversely affected. Fe 2 0 3 content after the above conversion is less than 50 mol%, and the ferrite containing CoO is more likely to have crystal grain growth than that with the same content of 50 mol% or more. Abnormal grain growth is likely to occur. Therefore, in order to make the squareness ratio 0.35 or less, it is particularly necessary to limit the contents of P, B, S and Cl to less than 50, 20, 30 and 50 ppm, respectively.
なお、Ｐ、Ｂ、ＳおよびClの含有量を上記の範囲に抑制するには、例えば原料となるFe2O3，MnＯ，ZnＯ等に関して、これらの不純物含有量の少ない、高純度原料を用いる必要がある。また、ボールミル等の、混合粉砕時に用いる媒体についても、磨耗による混入の恐れがあるため、これら不純物含有量の少ないものを用いることが望ましい。 In order to suppress the contents of P, B, S, and Cl within the above range, for example, high-purity raw materials having a small impurity content are used with respect to Fe 2 O 3 , MnO, ZnO and the like used as raw materials. There is a need. Also, a medium such as a ball mill used for mixing and pulverization may be mixed due to wear, so it is desirable to use a medium having a small content of these impurities.
CaO：0.005〜0.200mass％およびSiO2：0.001〜0.050mass％のうちから選んだ１種または２種
CaOおよびSiO2はいずれも、結晶粒界に偏析することによりフェライトの電気抵抗を高める効果があり、また粒成長時の粒界の移動速度を緩和させて粒内残留空孔を減らし、残留磁束密度を低下し最終的には角形比を低下する効果がある。これらの効果を得るには、CaO：0.005mass％以上およびSiO2：0.001mass％以上の添加が必要である。反対に多量に添加し過ぎた場合には、フェライト粒内の異常粒成長を誘発し比抵抗の低下と残留磁束密度の上昇をまねくことになる。さらに、これらの添加物は焼結密度の低下を招くことから過剰の添加は飽和磁束密度を低下させ、角形比の上昇を招く。そこで、上限はCaO：0.200mass％、SiO2：0.050mass％とすることが望ましい。
CaO: 0.005~0.200mass% and SiO 2: chose from among the 0.001~0.050mass% 1 alone or in combination of two or
Both CaO and SiO 2 have the effect of increasing the electrical resistance of ferrite by segregating at the grain boundaries, and also reducing the residual vacancies in the grains by relaxing the moving speed of the grain boundaries during grain growth. It has the effect of lowering the density and ultimately lowering the squareness ratio. In order to obtain these effects, it is necessary to add CaO: 0.005 mass% or more and SiO 2 : 0.001 mass% or more. On the other hand, if too much is added, abnormal grain growth in ferrite grains is induced, leading to a decrease in specific resistance and an increase in residual magnetic flux density. Furthermore, since these additives cause a decrease in the sintered density, excessive addition decreases the saturation magnetic flux density and increases the squareness ratio. Therefore, it is desirable that the upper limit is CaO: 0.200 mass% and SiO 2 : 0.050 mass%.
ZrO2：0.005〜0.100mass％、Ta2O5：0.005〜0.100mass％、HfO2：0.005〜0.100mass％およびNb2O5：0.005〜0.100mass％のうちから選んだ１種または２種以上
また、添加物として、ZrO2，Ta205，HfO2およびNb2O5を1種または2種以上添加しても良いものとする。これらの物質はいずれも、高い融点を持つ化合物であり、Mn−Co−Zn系フェライトに添加した場合には結晶粒を小さくする働きを持ち、そのため比抵抗を上昇させる。また、粒内残留空孔を減少させることから、残留磁束密度を低下する結果、角形比を低下する働きもある。しかし、添加量が適正な値よりも少ない場合には効果が得られず、また多量の場合には異常粒発生による比抵抗の低下と残留磁束密度の上昇をまねき、同時に焼結密度の低下から飽和磁束密度が低下して角形比の上昇を招く。そのため、それぞれ上記の範囲内に収めることが望ましい。
One or more selected from ZrO 2 : 0.005 to 0.100 mass%, Ta 2 O 5 : 0.005 to 0.100 mass%, HfO 2 : 0.005 to 0.100 mass% and Nb 2 O 5 : 0.005 to 0.100 mass% As additives, ZrO 2 , Ta 2 0 5 , HfO 2 and Nb 2 O 5 may be added singly or in combination. Any of these substances is a compound having a high melting point, and when added to the Mn-Co-Zn ferrite, has a function of reducing crystal grains, and thus increases the specific resistance. In addition, since the residual vacancies in the grains are reduced, the residual magnetic flux density is lowered, so that the squareness ratio is also lowered. However, if the added amount is less than the appropriate value, the effect is not obtained, and if the added amount is large, it leads to a decrease in specific resistance and an increase in residual magnetic flux density due to abnormal grain generation, and at the same time from a decrease in sintering density. The saturation magnetic flux density is lowered and the squareness ratio is increased. For this reason, it is desirable that each be within the above range.
V2O5：0.001〜0.100mass％、Bi2O3：0.001〜0.100mass％、In2O3：0.001〜0.100mass％、MoO3：0.001〜0.100mass％およびWO3：0.001〜0.100mass％のうちから選んだ１種または２種以上
さらに、本発明では添加物として、V2O5，Bi2O3，In2O3，MoO3およびWO3の１種または２種以上を添加しても良いものとする。これらの物質はいずれも、低い融点を持つ化合物であり、添加に伴いMn−Co−Zn系フェライトの焼結密度が上昇して飽和磁束密度が上昇することにより、角形比を低下させる働きを持つ。しかし、添加量が適切な値よりも少ない場合には効果が得られず、また多量の場合には異常粒成長の発生を招くため、それぞれ上記の範囲内に収めることが望ましい。
V 2 O 5 : 0.001 to 0.100 mass%, Bi 2 O 3 : 0.001 to 0.100 mass%, In 2 O 3 : 0.001 to 0.100 mass%, MoO 3 : 0.001 to 0.100 mass% and WO 3 : 0.001 to 0.100 mass% Further, in the present invention, one or more of V 2 O 5 , Bi 2 O 3 , In 2 O 3 , MoO 3 and WO 3 are added as additives in the present invention. It may be acceptable. All of these substances are compounds having a low melting point, and when added, the sintering density of the Mn-Co-Zn ferrite increases to increase the saturation magnetic flux density, thereby reducing the squareness ratio. . However, when the added amount is less than an appropriate value, the effect cannot be obtained, and when the added amount is large, abnormal grain growth occurs.
なお、上記にて群れ毎に解説した添加物は、その群れ毎の単独添加でも上記のとおり有効であるが、さらに複数の群れの組み合わせにて添加する場合でも、同様に効果を発揮する。その際も、異常粒成長の発生および角形比の上昇を抑えるため、その添加物量は上記の範囲内に抑えることが望ましい。 In addition, although the additive demonstrated for every group above is effective as above-mentioned even if individual addition for every group is carried out, even when it adds by the combination of a some group, it demonstrates an effect similarly. Also in that case, in order to suppress the occurrence of abnormal grain growth and the increase in the squareness ratio, it is desirable to suppress the amount of the additive within the above range.
次に、本発明のMn−Co−Zn系フェライトの好適な製造方法について説明する。
まず、所定の比率となるように、Fe2O3、ZnO、CoOおよびMnO粉末を秤量し、これらを十分に混合した後に仮焼を行う。次に、得られた仮焼粉を粉砕する。さらに、上記した添加物を加える際は、それらを所定の比率で加え、仮焼粉と同時に粉砕を行う。この作業で、添加した成分の濃度に偏りがないように粉末の充分な均質化を行う必要がある。目標組成の粉末をポリビニルアルコール等の有機物バインダーを用いて造粒し、圧力を加えて成形後適宜の焼成条件の下で焼成を行う。
Next, a preferred method for producing the Mn—Co—Zn ferrite of the present invention will be described.
First, Fe 2 O 3 , ZnO, CoO, and MnO powder are weighed so as to have a predetermined ratio, and after sufficiently mixing them, calcination is performed. Next, the obtained calcined powder is pulverized. Furthermore, when adding the above-mentioned additives, they are added at a predetermined ratio and pulverized simultaneously with the calcined powder. In this operation, it is necessary to sufficiently homogenize the powder so that the concentration of the added component is not biased. The powder of the target composition is granulated using an organic binder such as polyvinyl alcohol, and pressure is applied, followed by molding and firing under appropriate firing conditions.
ここで、本発明のMn−Co−Zn系フェライトは、不純物量が制限されているため、粉末冶金的手法を用いた際に問題となる異常粒成長や、焼成時の雰囲気の変動に対しても、角形比の上昇のような特性劣化を起こしにくい。そのため、上記のように、製造時に粉末冶金的な手法を用いることができ、さらに焼成の際の冷却時に、例えば酸素を１〜20体積ppm含む工業用の窒素を用いることが可能である。 Here, since the amount of impurities in the Mn-Co-Zn ferrite of the present invention is limited, the abnormal grain growth that becomes a problem when using a powder metallurgical technique and the fluctuation of the atmosphere during firing are considered. However, it is difficult to cause characteristic deterioration such as an increase in squareness ratio. Therefore, as described above, a powder metallurgical technique can be used at the time of production, and industrial nitrogen containing, for example, 1 to 20 ppm by volume of oxygen can be used at the time of cooling during firing.
かくして得られたMn−Co−Zn系フェライトは、Fe2＋量が従来のMn−Znフェライトに比べ大きく減少している。そのため、従来のMn−Znフェライトの問題点であった低い比抵抗が、0.1Ω・mオーダーから約300倍まで上昇する。また、Co添加による磁気異方性エネルギーの制御により、角形比は大幅に低下している。 In the Mn-Co-Zn ferrite thus obtained, the amount of Fe 2+ is greatly reduced as compared with the conventional Mn-Zn ferrite. Therefore, the low specific resistance, which has been a problem of the conventional Mn-Zn ferrite, increases from the order of 0.1 Ω · m to about 300 times. In addition, the squareness ratio is greatly reduced by controlling the magnetic anisotropy energy by adding Co.
含まれるFeおよびMnをすべてFe2O3およびMnOとして換算した場合に、Fe2O3，ZnO，CoOおよびMnOが表1に示す比率となるように秤量した各原料粉末を、ボールミルを用いて16時間混合した後、空気中で925℃および３時間の仮焼を行った。次に、ボールミルで12時間粉砕を行い、得られた混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm2の圧力をかけトロイダルコアを成形した。その後、この成形体を焼成炉に挿入して、最高温度1350℃で焼成を行い、焼成後の冷却の際には、1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
このようにして得られた各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。
得られた結果を表1に併記する。
When calculated as all the Fe and Mn Fe 2 O 3 and MnO contained, Fe 2 O 3, ZnO, respective raw material powders CoO and MnO were weighed so that the ratio shown in Table 1, using a ball mill After mixing for 16 hours, calcination was performed in air at 925 ° C. for 3 hours. Next, it was pulverized with a ball mill for 12 hours, polyvinyl alcohol was added to the obtained mixed powder and granulated, and a toroidal core was formed by applying a pressure of 1.2 ton / cm 2 . After that, this molded body is inserted into a firing furnace and fired at a maximum temperature of 1350 ° C. When cooling after firing, an industrial containing oxygen partial pressure of 10 volume ppm in the temperature range from 1100 ° C to 500 ° C A sintered core having an outer diameter of 30.5 mm, an inner diameter of 18.5 mm and a height of 6.3 mm was obtained.
About each sample obtained in this way, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density.
The obtained results are also shown in Table 1.
なお、酸化鉄をはじめとする原料は、すべて高純度なものを用いるため、Ｐ，Ｂ，Ｓ，Clの最終的な含有量は全ての試料でＰ，Ｂ，S，Clそれぞれ５ppmであった。 In addition, since all the raw materials including iron oxide use high-purity materials, the final contents of P, B, S, and Cl were 5 ppm for each sample in all of P, B, S, and Cl. .
同表に示したとおり、発明例である試料番号１−３、１−５および１−９では、キュリー温度が100℃以上、室温での比抵抗が30Ω・m以上かつ角形比が0.35以下、という優れた特性を有している。
これに対し、Fe2O3が50.0mol％以上の比較例（試料番号１−１および１−２）はいずれも、Fe2+を多く含有するために比抵抗が低く、その値は発明例の300分の１程度にとどまっている。反対に、Fe2O3が不足した比較例（試料番号１−10）では、角形比の上昇とキュリー温度の低下が確認された。
As shown in the table, Sample Nos. 1-3, 1-5, and 1-9, which are invention examples, have a Curie temperature of 100 ° C. or higher, a specific resistance at room temperature of 30 Ω · m or higher, and a squareness ratio of 0.35 or lower. It has excellent characteristics.
On the other hand, the comparative examples (sample numbers 1-1 and 1-2) in which Fe 2 O 3 is 50.0 mol% or more contain a large amount of Fe 2+ and have a low specific resistance. It remains at about 1 / 300th. On the contrary, in the comparative example (sample number 1-10) in which Fe 2 O 3 was insufficient, an increase in the squareness ratio and a decrease in the Curie temperature were confirmed.
また、CoOを含まない比較例（試料番号１−４）では、負の結晶磁気異方性を持つイオンから成るため、室温での角形比が大きな値をとっている。一方、CoOを多量に含む比較例（試料番号１−６）では、正の結晶磁気異方性の増大により、逆に角形比が上昇している。
さらに、ZnOに着目すると、発明範囲より多量に含む比較例（試料番号１−７）では、キュリー温度が100℃未満であり、実用上問題である。反対に不足した比較例（試料番号１−８）では、負の磁気異方性を持つイオンが増加したことから、角形比が上昇している。
Moreover, in the comparative example (sample number 1-4) which does not contain CoO, since it consists of ions having negative magnetocrystalline anisotropy, the squareness ratio at room temperature has a large value. On the other hand, in the comparative example (Sample Nos. 1-6) containing a large amount of CoO, the squareness ratio is increased due to the increase in positive magnetocrystalline anisotropy.
Further, focusing on ZnO, the comparative example (sample number 1-7) containing a larger amount than the scope of the invention has a Curie temperature of less than 100 ° C., which is a practical problem. On the other hand, in the comparative example (Sample Nos. 1-8) lacking, the number of ions having negative magnetic anisotropy increased, so the squareness ratio increased.
Ｐ、Ｂ、ＳおよびClの含有量が異なる種々の酸化鉄原料を使用し、試料における含有量が最終的に、P：50ppm以下、B：20ppm以下、S：30ppm以下およびCl：50ppm以下となるように計算した上で、含まれるFeおよびMnをすべてFe2O3およびMnOとして換算した場合に、表１における試料番号１−５と同組成となるように原料を秤量し、ボールミルを用いて16時間混合した後、空気中で925℃および３時間の仮焼を行った。次に、ボールミルで12時間粉砕を行い、得られた混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm2の圧力をかけてトロイダルコアを成形した。その後、この成形体を焼成炉に入れ、最高温度1350℃で焼成を行い、焼成後の冷却の際には、1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
これらの各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。なお、主成分組成により決まるキュリー温度は、全ての試料で120℃であった。
得られた結果を表２に示す。
Using various iron oxide raw materials with different contents of P, B, S and Cl, the content in the sample is finally P: 50 ppm or less, B: 20 ppm or less, S: 30 ppm or less, and Cl: 50 ppm or less. After calculating so that when Fe and Mn contained are all converted to Fe 2 O 3 and MnO, the raw materials are weighed so as to have the same composition as Sample Nos. 1-5 in Table 1, and a ball mill is used. After mixing for 16 hours, calcination was performed in air at 925 ° C. for 3 hours. Next, it was pulverized with a ball mill for 12 hours. Polyvinyl alcohol was added to the obtained mixed powder and granulated, and a toroidal core was formed by applying a pressure of 1.2 ton / cm 2 . Then, this compact is put into a firing furnace, fired at a maximum temperature of 1350 ° C, and when cooled after firing, industrial nitrogen containing oxygen partial pressure of 10 volume ppm in the temperature range from 1100 ° C to 500 ° C A sintered core having an outer diameter of 30.5 mm, an inner diameter of 18.5 mm, and a height of 6.3 mm was obtained.
For each of these samples, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density. The Curie temperature determined by the main component composition was 120 ° C. for all samples.
The obtained results are shown in Table 2.
同表に示したとおり、P，Ｂ，SおよびCl成分がそれぞれ50，20，30および50ppm未満の発明例（試料番号１−５，２−１）はいずれも、異常粒成長が見られず、高い比抵抗と低い角形比とが同時に得られている。
これに対し、不純物４種類のうち１成分でも適正な値より多く含む比較例（試料番号２−２〜２−７）はいずれも、異常粒が発生し、比抵抗および角形比ともに大きく劣化している。
As shown in the table, no abnormal grain growth was observed in any of the inventive examples (Sample Nos. 1-5 and 2-1) having P, B, S and Cl components of less than 50, 20, 30 and 50 ppm, respectively. A high specific resistance and a low squareness ratio are obtained at the same time.
On the other hand, all of the comparative examples (sample numbers 2-2 to 2-7) containing more than one appropriate component among the four types of impurities generate abnormal grains, and both the specific resistance and the squareness ratio are greatly deteriorated. ing.
実施例２と同組成の混合粉（但し、Ｐ，Ｂ，ＳおよびClはすべて５ppmに調整）に、添加物としてCaOおよびSiO2をそれぞれ最終組成が表３に示す比率となるよう添加し、ボールミルで12時間粉砕を行った。この混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm2の圧力を加えてトロイダルコアを成形し、その後、この成形体を焼成炉に入れ、最高温度1350℃で焼成を行い焼成後の冷却の際には、1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
これらの各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。なお、主成分組成により決まるキュリー温度は、全ての試料で120℃であった。
得られた結果を表３に併記する。
To the mixed powder having the same composition as in Example 2 (however, P, B, S and Cl are all adjusted to 5 ppm), CaO and SiO 2 are added as additives so that the final composition has the ratio shown in Table 3, respectively. Grinding was performed for 12 hours with a ball mill. This mixed powder is granulated by adding polyvinyl alcohol, and a toroidal core is formed by applying a pressure of 1.2 ton / cm 2. After that, the formed body is placed in a firing furnace and fired at a maximum temperature of 1350 ° C. When cooling, the sintered body with an outer diameter of 30.5mm, an inner diameter of 18.5mm, and a height of 6.3mm is performed in an industrial nitrogen flow containing oxygen partial pressure of 10 volume ppm in the temperature range from 1100 ℃ to 500 ℃ Got the core.
For each of these samples, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density. The Curie temperature determined by the main component composition was 120 ° C. for all samples.
The results obtained are also shown in Table 3.
表3の結果から、CaOおよびSiO2の１種または２種を添加した発明例（試料番号３−１〜３−３）に関しては、比抵抗が上昇し、また粒内残留空孔の減少から残留磁束密度が低下し、角形比が低下している。しかし、CaOおよびSiO2のどちらか一方でも適正な値より多く含む比較例（試料番号３−４〜３−６）ではいずれも異常粒が発生し、粒内に多数の不純物や空孔を含むために比抵抗が低下し、また残留磁束密度が上昇することから角形比が上昇している。 From the results of Table 3, with respect to the invention examples (Sample Nos. 3-1 to 3-3) to which one or two of CaO and SiO 2 were added, the specific resistance increased and the residual pores in the grains decreased. The residual magnetic flux density is reduced and the squareness ratio is reduced. However, in any of the comparative examples (sample numbers 3-4 to 3-6) including more than one of CaO and SiO 2 in an appropriate value, abnormal grains are generated, and many impurities and vacancies are included in the grains. For this reason, the specific resistance is decreased, and the residual magnetic flux density is increased, so that the squareness ratio is increased.
実施例２と同組成の混合粉（但し、Ｐ，Ｂ，ＳおよびClはすべて５ppmに調整）に、添加物としてNb2O5，TaO2，HfO2およびZrO2をそれぞれ最終組成が表４に示す比率となるよう添加し、ボールミルで12時間粉砕を行った。この混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm2の圧力を加えてトロイダルコアを成形し、その後、この成形体を焼成炉に入れ、最高温度1350℃で焼成を行い、焼成後の冷却の際には1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
これらの各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。なお、主成分組成により決まるキュリー温度は、全ての試料で120℃であった。
得られた結果を表４に併記する。
The final composition of Nb 2 O 5 , TaO 2 , HfO 2 and ZrO 2 was added to the mixed powder having the same composition as in Example 2 (however, P, B, S and Cl were all adjusted to 5 ppm) as additives. The mixture was added so as to have the ratio shown in FIG. This mixed powder is granulated by adding polyvinyl alcohol, and a toroidal core is formed by applying a pressure of 1.2 ton / cm 2 , and then the formed body is placed in a firing furnace and fired at a maximum temperature of 1350 ° C. During subsequent cooling, it is performed in an industrial nitrogen flow containing oxygen partial pressure of 10 ppm by volume in the temperature range from 1100 ° C to 500 ° C. The sintered body has an outer diameter of 30.5mm, an inner diameter of 18.5mm, and a height of 6.3mm. Got the core.
For each of these samples, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density. The Curie temperature determined by the main component composition was 120 ° C. for all samples.
The obtained results are also shown in Table 4.
表4の結果から、Nb2O5，TaO2，HfO2およびZrO2を１種または２種以上適量添加した発明例（試料番号４−１〜４−15）はいずれも、結晶の成長が抑制された結果、比抵抗が上昇した。
また、粒内残留空孔の減少により残留磁束密度が低下し、よって角形比も低下している。
From the results in Table 4, all of the inventive examples (Sample Nos. 4-1 to 4-15) to which one or more appropriate amounts of Nb 2 O 5 , TaO 2 , HfO 2 and ZrO 2 were added had crystal growth. As a result, the specific resistance increased.
Further, the residual magnetic flux density is lowered due to the reduction of the intragranular residual vacancies, and thus the squareness ratio is also lowered.
しかし、Nb2O5，TaO2，HfO2およびZrO2の４成分のうち１種類でも適正範囲を超えて多量に含有する比較例（試料番号４−16〜４−18）ではいずれも、異常粒が発生し、粒内に多数の不純物や空孔を含むために比抵抗が低下し、また残留磁束密度が上昇することから角形比が上昇している。 However, any of the four components of Nb 2 O 5 , TaO 2 , HfO 2 and ZrO 2 is abnormal in any of the comparative examples (sample numbers 4-16 to 4-18) containing a large amount exceeding the appropriate range. Grains are generated, and a large number of impurities and vacancies are contained in the grains, so that the specific resistance is lowered, and the residual magnetic flux density is increased, so that the squareness ratio is increased.
実施例２と同組成の混合粉（但し、Ｐ，Ｂ，ＳおよびClはすべて５ppmに調整）に、添加物としてV2O5，Bi2O3，In2O3，MoO3およびWO3をそれぞれ最終的に表５に示す比率となるように添加し、ボールミルで12時間粉砕を行った。この混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm2の圧力を加えてトロイダルコアを成形し、その後、この成形体を焼成炉に入れ最高温度1350℃で焼成を行い、焼成後の冷却の際には1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
これらの各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。なお、主成分組成により決まるキュリー温度は、全ての試料で120℃であった。
得られた結果を表５に併記する。
V 2 O 5 , Bi 2 O 3 , In 2 O 3 , MoO 3 and WO 3 were added to the mixed powder having the same composition as in Example 2 (however, P, B, S and Cl were all adjusted to 5 ppm). Were finally added so as to have the ratios shown in Table 5, and pulverized with a ball mill for 12 hours. This mixed powder is granulated by adding polyvinyl alcohol, and a toroidal core is formed by applying a pressure of 1.2 ton / cm 2 , and then the formed body is placed in a firing furnace and fired at a maximum temperature of 1350 ° C. When cooling the steel core, it is carried out in an industrial nitrogen flow containing oxygen partial pressure of 10 ppm by volume in the temperature range from 1100 ° C to 500 ° C, and a sintered core with an outer diameter of 30.5mm, an inner diameter of 18.5mm and a height of 6.3mm Got.
For each of these samples, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density. The Curie temperature determined by the main component composition was 120 ° C. for all samples.
The obtained results are also shown in Table 5.
表5の結果から、V2O5，Bi2O3，In2O3，MoO3およびWO3の１種または２種以上を適量添加した本発明（試料番号５−１〜５−31）はいずれも、結晶粒の成長および焼結密度の上昇が見られ、飽和磁束密度が上昇することから角形比が低下している。
これに対し、５成分のうちどれか1つでも適正な値より多く含む比較例（試料番号５−32，５−33）はいずれも、異常粒が発生し、粒内に多数の不純物や空孔を含むために比抵抗が大きく低下し、また残留磁束密度が上昇することから角形比が上昇している。
From the results of Table 5, the present invention in which one or more of V 2 O 5 , Bi 2 O 3 , In 2 O 3 , MoO 3 and WO 3 were added in an appropriate amount (sample numbers 5-1 to 5-31) In both cases, the growth of crystal grains and the increase in the sintered density are observed, and the saturation magnetic flux density is increased, so that the squareness ratio is decreased.
On the other hand, in any of the comparative examples (sample numbers 5-32 and 5-33) containing any one of the five components in excess of the appropriate value, abnormal grains are generated, and a large number of impurities and voids are present in the grains. Since the hole is included, the specific resistance is greatly reduced, and the residual magnetic flux density is increased, so that the squareness ratio is increased.
実施例２と同組成の混合粉（但し、Ｐ，Ｂ，ＳおよびClはすべて５ppmに調整）に、副成分として、CaOおよびSiO2のいずれか１種又は２種（添加物群Ａ）、ZrO2，TaO2，HfO2およびNb2O5のいずれか１種又は２種以上（添加物群Ｂ）そしてV2O5，Bi2O3，In2O3，MoO3およびWO3のいずれか１種又は２種以上（添加物群Ｃ）を、最終成分が表６に示す通りになるようにそれぞれ添加し、ボールミルで12時間粉砕を行った。この混合粉にポリビニルアルコールを加えて造粒し、1.2ton／cm２の圧力を加えてトロイダルコアを成形し、その後、この成形体を焼成炉に入れ、最高温度1350℃で焼成を行い焼成後の冷却の際には、1100℃から500℃までの温度範囲で酸素分圧10体積ppmを含む工業用窒素流中で行い、外径30.5mm、内径18.5mmおよび高さ6.3mmの焼結体コアを得た。
これらの各試料について、比抵抗を測定し、また飽和磁束密度および残留磁束密度を測定して角形比を算出した。なお、主成分組成により決まるキュリー温度は、全ての試料で120℃であった。
得られた結果を表６に併記する。
To the mixed powder having the same composition as in Example 2 (however, P, B, S and Cl are all adjusted to 5 ppm), any one or two of CaO and SiO 2 (additive group A) as subcomponents, Any one or more of ZrO 2 , TaO 2 , HfO 2 and Nb 2 O 5 (additive group B) and V 2 O 5 , Bi 2 O 3 , In 2 O 3 , MoO 3 and WO 3 Any one or more (additive group C) was added so that the final components were as shown in Table 6, and pulverized for 12 hours with a ball mill. Polyvinyl alcohol is added to this mixed powder and granulated, and a toroidal core is formed by applying a pressure of 1.2 ton / cm 2. After that, the formed body is placed in a firing furnace and fired at a maximum temperature of 1350 ° C. When cooling, the sintered body with an outer diameter of 30.5mm, an inner diameter of 18.5mm, and a height of 6.3mm is performed in an industrial nitrogen flow containing oxygen partial pressure of 10 volume ppm in the temperature range from 1100 ℃ to 500 ℃ Got the core.
For each of these samples, the specific resistance was measured, and the squareness ratio was calculated by measuring the saturation magnetic flux density and the residual magnetic flux density. The Curie temperature determined by the main component composition was 120 ° C. for all samples.
The obtained results are also shown in Table 6.
表6に示したとおり、添加物群Ａ〜Ｃを組み合わせて添加した発明例（試料番号６−１〜６−27）はいずれも、これらが無添加の場合と比べて比抵抗が上昇し、角形比が低下した。
これに対し、これら11成分のうちどれか1つでも適正な値より多く含む比較例（試料番号６−28〜６−30）ではいずれも異常粒が発生し、粒内に多数の不純物や空孔を含むために比抵抗が低下し、また残留磁束密度が上昇することから角形比が上昇している。
As shown in Table 6, the invention examples (Sample Nos. 6-1 to 6-27) added in combination with the additive groups A to C increased in specific resistance as compared with the case where they were not added, The squareness ratio decreased.
On the other hand, in any of the comparative examples (sample numbers 6-28 to 6-30) containing any one of these 11 components in excess of the appropriate value, abnormal grains are generated, and many impurities and vacancies are formed in the grains. Since the specific resistance decreases due to the inclusion of the holes and the residual magnetic flux density increases, the squareness ratio increases.
Claims (4)
CoO：0.5mol％以上4.0mol％以下、
ZnO：15.5mol％以上24.0mol％以下および
MnO：残部
を基本成分とし、
フェライト中に含まれるＰ、Ｂ、ＳおよびClが、
Ｐ：50massppm未満、
Ｂ：20massppm未満、
Ｓ：30massppm未満および
Cl：50massppm未満
であることを特徴とするMn−Co−Zn系フェライト。 Fe 2 O 3 : 45.0 mol% or more and less than 50.0 mol%,
CoO: 0.5 mol% or more and 4.0 mol% or less,
ZnO: 15.5 mol% to 24.0 mol% and
MnO: The balance is the basic component,
P, B, S and Cl contained in the ferrite are
P: less than 50 massppm,
B: Less than 20 massppm
S: less than 30 massppm and
Cl: Mn-Co-Zn ferrite characterized by being less than 50 massppm.
CaO：0.005〜0.200mass％および
SiO2：0.001〜0.050mass％
のうちから選んだ１種または２種を含有する請求項１に記載のMn−Co−Zn系フェライト。 In the ferrite, further as an additive
CaO: 0.005-0.200 mass% and
SiO 2 : 0.001 to 0.050 mass%
The Mn-Co-Zn-based ferrite according to claim 1, containing one or two selected from among them.
ZrO2：0.005〜0.100mass％、
Ta2O5：0.005〜0.100mass％、
HfO2：0.005〜0.100mass％および
Nb2O5：0.005〜0.100mass％
のうちから選んだ１種または２種以上を含有する請求項１または２に記載のMn−Co−Zn系フェライト。 In the ferrite, further as an additive
ZrO 2 : 0.005 to 0.100 mass%,
Ta 2 O 5 : 0.005 to 0.100 mass%,
HfO 2 : 0.005 to 0.100 mass% and
Nb 2 O 5 : 0.005 to 0.100 mass%
The Mn—Co—Zn-based ferrite according to claim 1, comprising one or more selected from among the above.
V2O5：0.001〜0.100mass％、
Bi2O3：0.001〜0.100mass％、
In2O3：0.001〜0.100mass％、
MoO3：0.001〜0.100mass％および
WO3：0.001〜0.100mass％
のうちから選んだ１種または２種以上を含有する請求項１、２または３に記載のMn−Co−Zn系フェライト。 In the ferrite, further as an additive
V 2 O 5 : 0.001 to 0.100 mass%,
Bi 2 O 3 : 0.001 to 0.100 mass%,
In 2 O 3 : 0.001 to 0.100 mass%,
MoO 3 : 0.001 to 0.100 mass% and
WO 3: 0.001~0.100mass%
4. The Mn—Co—Zn-based ferrite according to claim 1, comprising one or more selected from among the above.
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| JP4554959B2 (en) * | 2004-03-05 | 2010-09-29 | Ｊｆｅケミカル株式会社 | Mn-Co-Zn ferrite |
| JP4554960B2 (en) * | 2004-03-05 | 2010-09-29 | Ｊｆｅケミカル株式会社 | Mn-Co-Zn ferrite |
| JP4554965B2 (en) * | 2004-03-24 | 2010-09-29 | Ｊｆｅケミカル株式会社 | Mn-Co-Zn ferrite |
| CN100400462C (en) * | 2005-08-11 | 2008-07-09 | 横店集团东磁有限公司 | Mn-Zn ferrite material |
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| JP2010180101A (en) * | 2009-02-06 | 2010-08-19 | Jfe Chemical Corp | HIGH RESISTANCE AND HIGHLY SATURATED MAGNETIC FLUX DENSITY MnZnCo FERRITE, AND METHOD FOR PRODUCING THE SAME |
| JP4752934B2 (en) * | 2009-03-05 | 2011-08-17 | Ｔｄｋ株式会社 | Radio wave absorber and manufacturing method thereof |
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| CN104261812A (en) * | 2014-09-11 | 2015-01-07 | 麦格磁电科技（珠海）有限公司 | Anti-EMI (electromagnetic interference) ferrite material and preparation method thereof |
| JP6964556B2 (en) * | 2017-06-23 | 2021-11-10 | Ｊｆｅケミカル株式会社 | MnZnNiCo-based ferrite and its manufacturing method |
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| JP6964555B2 (en) * | 2018-05-16 | 2021-11-10 | Ｊｆｅケミカル株式会社 | MnZnNiCo-based ferrite and its manufacturing method |
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