JP4471249B2 - Magnetic material - Google Patents
Magnetic material Download PDFInfo
- Publication number
- JP4471249B2 JP4471249B2 JP2000268192A JP2000268192A JP4471249B2 JP 4471249 B2 JP4471249 B2 JP 4471249B2 JP 2000268192 A JP2000268192 A JP 2000268192A JP 2000268192 A JP2000268192 A JP 2000268192A JP 4471249 B2 JP4471249 B2 JP 4471249B2
- Authority
- JP
- Japan
- Prior art keywords
- transition
- magnetic
- exhibits
- magnetostriction
- hydrogen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Micromachines (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、磁歪が大きく、磁気−機械変位変換デバイス等に用いられる磁歪素子用として好適な、メタ磁性転移を発現する磁性体に関する。
【０００２】
【従来の技術】
磁性体に外部磁界を印加した際生じる歪である磁歪の応用として、磁歪フィルタ、磁歪センサ、超音波遅延線、磁歪振動子等がある。従来はＮｉ基合金、Ｆｅ−Ｃｏ合金、フェライト、ラーベス型金属間化合物（Ｔｂ，Ｄｙ，Ｓｍ）Ｆｅ2等が用いられている。
【０００３】
近年、計測工学の進歩及び精密機械分野の発展に伴い、ミクロンオーダーの微小変位制御に不可欠の変位駆動部の開発が必要とされている。この変位駆動部の駆動機構の一つとして、磁歪物質を用いた磁気−機械変換デバイスが有力である。しかしながら、従来の磁歪材料では変位の絶対量が十分でなく、ミクロンオーダーの精密変位制御駆動部材料としては絶対駆動変位量のみならず、精密制御の点からも満足し得るものではなかった。
【０００４】
通常、超磁歪材料と呼ばれているものは、ＲｅＦｅ2であらわされるラーベス型金属間化合物のうち、ＴｂＦｅ2（λｓ＝１７５３×１０-6）やＳｍＦｅ2（λｓ＝−１５６０×１０-6）〔Ｃｌａｒｋ（１９７４）：超磁歪材料、日刊工業新聞社刊〕があり、最も大きな飽和磁歪値を持っている。また、磁性の大きさだけをみれば、２００Ｋ以下の低温においてＤｙやＴｂの単結晶で大きな磁歪（λｓ〜±４０００×１０-6）が得られている。これらのものを例示すれば表１のとおりである。
【０００５】
【表１】
【０００６】
【発明が解決しようとする課題】
従来の磁歪材料は、磁歪が大きくても液体窒素温度以下であったり、実際の磁歪が小さい問題や、磁歪が異方性であるために、印加磁界をかける方向が限定され、デバイスの構造に制約を受ける問題があり、これらを解決する高性能の磁歪材料が期待されている。
【０００７】
本発明はこのような問題点を考慮してなされたもので、等方的な磁歪を有し、かつ、室温近傍で従来までの磁歪効果を越えるような大きな磁歪を有する、メタ磁性転移を発現する磁性体を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明は、下記各項よりなる。
（１）一般式：Ｌａ（Ｆｅ1-xＡx）13- δＤq（ただし、ＡはＡｌ，Ｓｉ，Ｇａ，Ｇｅ，Ｓｎのうち少なくとも１種の元素、Ｄは水素、窒素のうち少なくとも１種の元素、ｘ，δ，ｑは原子比で０．０５≦ｘ≦０．２、−１≦δ≦１、０＜ｑ＜２）で示される組成からなるメタ磁性転移を発現する磁性体。
【０００９】
（２）一般式：Ｌａ（Ｆｅ1-xＡx-yＴＭy）13- δＤq（ただし、ＡはＡｌ，Ｓｉ，Ｇａ，Ｇｅ，Ｓｎのうち少なくとも１種の元素、ＴＭはＦｅを除く遷移金属元素のうち少なくとも１種の元素、Ｄは水素、窒素のうち少なくとも１種の元素、ｘ，ｙ，δ，ｑは原子比で０．０５≦ｘ≦０．２、０＜ｙ＜０．１、−１≦δ≦１、０＜ｑ＜２）で示される組成からなるメタ磁性転移を発現する磁性体。
【００１０】
（３）一般式：Ｌａ1-zＲＥz（Ｆｅ1-xＡx）13- δＤq（ただし、ＡはＡｌ，Ｓｉ，Ｇａ，Ｇｅ，Ｓｎのうち少なくとも１種の元素、ＲＥはＬａを除く希土類元素のうち少なくとも１種の元素、Ｄは水素、窒素のうち少なくとも１種の元素、ｘ，ｚ，δ，ｑは原子比で０．０５≦ｘ≦０．２、０＜ｚ≦０．１、−１≦δ≦１、０＜ｑ＜２）で示される組成からなるメタ磁性転移を発現する磁性体。
【００１１】
（４）一般式：Ｌａ1-zＲＥz（Ｆｅ1-xＡx-yＴＭy）13- δＤq（ただし、ＡはＡｌ，Ｓｉ，Ｇａ，Ｇｅ，Ｓｎのうち少なくとも１種の元素、ＴＭはＦｅを除く遷移金属元素のうち少なくとも１種の元素、ＲＥはＬａを除く希土類元素のうち少なくとも１種の元素、Ｄは水素、窒素のうち少なくとも１種の元素、ｘ，ｙ，ｚ，δ，ｑは原子比で０．０５≦ｘ≦０．２、０＜ｙ＜０．１、ｘ＞ｙ、０＜ｚ≦０．１、−１≦δ≦１、０＜ｑ＜２）で示される組成からなるメタ磁性転移を発現する磁性体。
【００１２】
（５）一般式：Ｌａ（Ｆｅ1-a-bＳｉaＣｏ b）13Ｄq（ただし、Ｄは水素、窒素のうち少なくとも１種の元素、０．１０≦ａ≦０．１６、０＜ｂ≦０．０８、０＜ｑ＜２）で示される組成からなるメタ磁性転移を発現する磁性体。
【００１３】
（６）ＴＭがＣｏ，Ｎｉ，Ｃｕのうちの少なくとも１種の元素である前記（２）又は（４）記載のメタ磁性転移を発現する磁性体。
【００１４】
ＲＥがＹ，Ｃｅ，Ｐｒ，Ｎｄ，Ｐｍ，Ｓｍ，Ｅｕ，Ｇｄ，Ｔｂ，Ｄｙ，Ｈｏ，Ｅｒ，Ｔｍ，Ｙｂ，Ｌｕのうちの少なくとも１種の元素である前記（３）又は（４）記載のメタ磁性転移を発現する磁性体。
【００１５】
（７）１０原子％以下で不可避的不純物を含む前記（１）ないし（６）のいずれかに記載のメタ磁性転移を発現する磁性体。
【００１６】
体積率で９０％以上が立方晶系のＮａＺｎ13型金属間化合物である前記（１）ないし（７）のいずれかに記載のメタ磁性転移を発現する磁性体。
【００１７】
本発明材料の基となるＬａ（Ｆｅ1-xＡx）13に関して、Ｌａは２０面体を構成するＦｅ1-xＡxによりＢＣＣ的に取り込まれており、Ａ＝Ｓｉとした場合、Ｓｉ量（ｘ）を変えることで磁気転移温度Ｔｃ（キュリー温度）、ＴＮ（ネール温度）及び磁化Ｍｓが変化することは知られている〔Ｋ．Ｈ．Ｊ．Ｂｕｓｃｈｏｗ等、Ｊｏｕｒｎａｌ ｏｆ Ｍａｇｎｅｔｉｓｍ ａｎｄ Ｍａｇｎｅｔｉｃ Ｍａｔｅｒｉａｌｓ ３６（１９８３）１９０−２９６〕。
【００１８】
本発明者らはこの材料について詳細な検討を進めた結果、Ｆｅの置換元素であるＡの元素をＳｉ，Ａｌ，Ｇａ，Ｇｅ，Ｚｎの少なくとも１種とし、そのｘの量を変化させることで、ｘが小さい組成で、低温ではあるが、反強磁性から強磁性へのメタ磁性転移を起こすことを見出し、さらにはメタ磁性転移により飽和磁歪（λｓ）が５０００×１０-6を越えるものが得られることが判った。ここでメタ磁性転移とは、反強磁性もしくは常磁性状態に磁界を印加することで、強磁性体に変化する現象である。
【００１９】
この材料は、従来のＴｂＦｅ2などラーベス型磁歪材料が磁界方向に対し磁歪の大きさが平行と直角では伸縮が逆（符号が逆）と異方的であるのに対し、Ｌａ（Ｆｅ1-xＡx）13は磁界を印加することで全ての方向に対して伸びる。言い換えれば磁界をかけることで体積が増えることとなり、従来の巨大磁歪材料とは全く異なる磁歪効果を示す。この材料の組成、Ｆｅの置換元素であるＡの元素およびＣｏの置換量、Ｌａの置換元素である希土類元素の置換量を検討した結果、室温近傍で大きな磁歪を示す材料を得ることが可能となった［特開２０００−５４０８６］。しかしながら、磁歪を室温近傍で発現させるためには、組成を厳密に制御し、また材料作製方法、調製方法にも細心の注意を要する。
【００２０】
本発明者等は室温以上で超磁歪効果を容易に発現させるために、材料の結晶構造に着目し、構造制御することを試みた。Ｌａ（Ｆｅ1-xＳｉx）13に圧力を加えることでＴｃは低下する。また、Ｌａ（Ｆｅ1-xＳｉx）13ではＳｉ量が増加するに従い磁気転移温度は上昇する［特開２０００−５４０８６］。
【００２１】
これは、図１で示すような２０面体を構成するＦｅ1-xＡx中のＦｅがＳｉに置き換わることで平均的なＦｅ−Ｆｅ間距離が広がりＴｃが上昇する。また逆に、Ｌａ（Ｆｅ1-xＳｉx）13に圧力を加えることでＴｃが低下することも分かっている。
【００２２】
このような背景から、本発明者等は本材料に対し侵入型の元素を添加し、結晶構造を変えることなくＬａ（Ｆｅ1-xＳｉx）13のＦｅ−Ｆｅ間相互作用の制御、言い換えれば磁気転移温度の制御を行った。
【００２３】
図２は、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13の磁化Ｍおよび歪み△Ｌ／Ｌの温度依存性および磁界依存性を示した図である。Ｌａ（Ｆｅ0.88Ｓｉ0.12）13は温度を上げていくと、Ｔｃ＝１９５Ｋで磁化が減少し、強磁性体から常磁性体に変化し、同時に歪み△Ｌ／ＬもＴｃ＝１９５Ｋで減少する。また、Ｔｃ＝１９５Ｋ近傍の２００Ｋでの磁化は常磁性体であるが磁界を印加することで強磁性体に変化するメタ磁性転移を示し、それに伴い歪み△Ｌ／Ｌは増加する。このように、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13の歪み△Ｌ／Ｌは磁化Ｍとよい相関を示す。Ｔｃ直下の常磁性のＬａ（Ｆｅ0.88Ｓｉ0.12）13に磁界をかけることで、常磁性体から強磁性体に相変化（メタ磁性転移）し、格子定数の増加、体積増加が生じることが本材料の磁歪効果である。このように本材料は磁界を印加させることで大きな体積変化を生じさせるだけでなく、Ｔｃ近傍での温度変化によっても大きな体積変化を生じることが特徴である。
【００２４】
Ｌａ（Ｆｅ0.88Ｓｉ0.12）13に水素を吸蔵させた場合の、Ｘ線回折図を図３に示す。一番下に示すのはＮａＺｎ13型のＸ線回折線であるが、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13およびＬａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ1.6はいずれもＮａＺｎ13型を示し、水素を吸蔵することで各回折線は低角側にずれており、全体的に格子定数が大きくなっていることが分かる。この材料の熱膨張測定を行った結果を図４に示す。熱膨張△Ｌ／Ｌは温度を上昇させるとＴｃで大きな低下を示し、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13のＴｃが１９０Ｋであるのに対し、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ1.6はＴｃ＝３３３Ｋと室温（３００Ｋ）を大きく越える。従って、図４で示したようなＴｃ近傍での大きな磁歪効果は、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ1.6の場合、５０℃（３３３Ｋ）で大きな磁歪効果を示すことがいえる。さらに図５に示すようにＴｃは水素吸蔵量を少なくすることで低下することができるためＴｃ以下の任意の温度で大きな磁歪効果を示すことができる。このとき水素は図１のＮａＺｎ13単位胞中のＦｅI−ＦｅIの中間に配位している。
【００２５】
図６はＬａ（Ｆｅ0.88Ｓｉ0.12）13Ｈqの水素吸蔵量を変えた時の、磁気転移温度（キュリー温度）と室温での格子定数 を示す。水素量を変えることで、Ｔｃは１９０Ｋ（−８３℃）から３４０Ｋ（６７℃）まで大きく変化させることが可能である。このときの水素吸蔵量の増加によって室温の格子定数は増加し、それに伴ってキュリー温度Ｔｃが上昇する。Ｔｃが室温を超えるとＬａ（Ｆｅ0.88Ｓｉ0.12）13Ｈqは室温で強磁性体から常磁性体に変わるため、格子定数は不連続に増加する。
【００２６】
図７は、Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ１．６（Ｔｃ＝３３３Ｋ）の各温度（３３０、３３６、３３８、３４２Ｋ）における磁化曲線で、Ｔｃ直上以上では常磁性で磁化はないが、磁界を印加すると磁化があらわれ、大きな磁歪が生じる。Ｔｃから高くなるに従い、磁歪効果を生じさせるためには高磁界が必要になり、大きな磁歪を高感度に生じさせるには本材料を（Ｔｃ−５）Ｋから（Ｔｃ＋１０）Ｋの範囲で使用するのが望ましい。好ましくはＴｃ±５Ｋで使用するのがよい。
【００２７】
本発明では、Ｆｅの置換元素であるＡの元素はＳｉ，Ａｌ，Ｇａ，Ｇｅ，Ｚｎの少なくとも１種であり、ＦｅとＡの比は、Ａの比が増加するに従い、磁気転移温度は上昇し、飽和磁化は小さくなる。Ｌａ（Ｆｅ1-xＡx）13では、総じてｘが０．０５未満であるとＮａＺｎ13型の結晶構造を維持することができず、磁歪を発現するメタ磁性転移がなくなる。一方、ｘが０．３を越えると強磁性状態が安定となり、同様に磁歪を発現するメタ磁性転移は認められなくなる。そこで、本発明では好適な範囲として０．０５≦ｘ≦０．２とした。請求項２などにおけるＴＭ（Ｃｏ，Ｎｉ，Ｃｕ）の量が変わることで磁性を担うＦｅの３ｄ電子の数が変わり、磁気転移温度Ｔｃおよび磁化（Ｍｓ）の強さを変える効果がある。このときのｙの組成は０≦ｙ＜０．１の範囲で変えることが好適で、ｙが０．１以上となるとＦｅの磁性そのものに影響を及ぼすために磁歪を発現するメタ磁性転移が生じなくなり不適である。特にＴＭがＣｏの場合、置換元素Ｃｏの組成が変わることで磁性を担うＦｅの３ｄ電子の数が変わり、磁気転移温度Ｔｃ、ＴＮおよび磁化の強さを変える効果がある。このときＣｏの組成（ｙ）は、０＜ｙ≦０．０８の範囲で変えることが好適で、ｙが０．０８を越えると、Ｆｅの磁性そのものに影響を及ぼすために磁歪を発現するメタ磁性転移が生じなくなり不適である。好ましくはＣｏの組成は０．０４≦ｙ≦０．０６が磁気転移温度Ｔｃを上昇させ、室温近傍での磁歪効果を得ることで効果的である。
【００２８】
また請求項３、４においてＬａの一部を他の希土類元素（Ｎｄ，Ｇｄなど）で置換することで飽和磁界を小さくする効果がある。置換量（ｚ）の上限は０．１である。ｚが０．１を越えるとＮａＺｎ13型の化合物構造をとるよりもＲＥ2Ｆｅ17が安定となり、ＮａＺｎ13構造によるメタ磁性転移が生じなくなり、結果として巨大磁歪が得られない。
【００２９】
また請求項１、２、３、４、５において、（Ｈ，Ｎ）をＮａＺｎ13型の化合物構造中に侵入させることでＦｅ−Ｆｅ合金の相互作用を変化させ、磁気転移温度を上昇させる効果がある。このとき水素量がｑ≧２となるとＮａＺｎ13型の結晶構造を維持することができず、磁歪を発現するメタ磁性転移がなくなる。一方、窒素量はｑ＞１．６以上でＮａＺｎ13型の結晶構造を維持することができず、磁歪を発現するメタ磁性転移がなくなる。結果として巨大磁歪が得られない。また、本発明では１０原子％の不可避的不純物を含んでも差し支えない。
【００３０】
【発明の実施の形態】
以下、本発明の実施例について述べる。表２に示した組成の材料をアーク溶解にて作製した後、真空中、１０５０℃で１６８時間熱処理した試料をダイヤモンドカッターで切り出した。磁化特性、熱磁特性はＳＱＵＩＤ（カンタムデザイン社製）を用い、磁歪は超電導磁石中、４．２Ｋから３７３Ｋまで静電容量法を用いて測定した。磁化、熱磁測定用試料及び磁歪測定用試料の形状は２ｍｍ×２ｍｍ×２ｍｍに切り出して用いた。
【００３１】
その結果、表２に示すような組成において室温近傍から１００℃の温度範囲で、この場合（２５０Ｋ−４００Ｋ）でメタ磁性転移温度を持つ、言い換えれば非常に大きな磁歪特性を示す。
【００３２】
【表２】
【００３３】
【発明の効果】
以上説明したとおり本発明のメタ磁性転移を発現する磁性体は従来の材料の特性に比べて、等方的できわめて大きな磁歪特性を室温以上で有する。これによりμｍオーダーの微小変位制御駆動部、強力音波発生用振動子、センサ等の構成材料として極めて優れた特性を有するものである。
【図面の簡単な説明】
【図１】 ＮａＺｎ13型結晶構造Ｌａ（ＦｅＡｌ，Ｓｉ）13を示す。
【図２】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13の磁化Ｍと歪み量△Ｌ／Ｌの温度依存性および磁界依存性を示すグラフである。
【図３】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈq（ｑ＝０．０，１．６）のＸ線回折図を示す。
【図４】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈq（ｑ＝０．０，１．６）の歪み△Ｌ／Ｌの温度依存性を示すグラフである。
【図５】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ1.6の水素を放出した場合のＴｃの変化を示すグラフである。
【図６】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈqのキュリー温度（Ｔｃ）と室温での格子定数を示す。
【図７】 Ｌａ（Ｆｅ0.88Ｓｉ0.12）13Ｈ1.6（Ｔｃ＝３３３Ｋ）の各温度（３３０、３３６、３３８、３４２Ｋ）における磁化曲線を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic body that exhibits a metamagnetic transition and has a large magnetostriction and is suitable for a magnetostrictive element used in a magneto-mechanical displacement conversion device.
[0002]
[Prior art]
Applications of magnetostriction, which is strain generated when an external magnetic field is applied to a magnetic material, include a magnetostrictive filter, a magnetostrictive sensor, an ultrasonic delay line, a magnetostrictive vibrator, and the like. Conventionally, Ni-based alloys, Fe—Co alloys, ferrites, Laves-type intermetallic compounds (Tb, Dy, Sm) Fe 2 and the like have been used.
[0003]
In recent years, with the advancement of measurement engineering and the development of the precision machine field, it is necessary to develop a displacement drive unit indispensable for micro displacement control on the order of microns. As one of the drive mechanisms of the displacement drive unit, a magneto-mechanical conversion device using a magnetostrictive material is promising. However, the absolute amount of displacement is not sufficient in the conventional magnetostrictive material, and the precision displacement control drive part material of micron order is not satisfactory from the point of precision control as well as the absolute drive displacement amount.
[0004]
Usually, what is called a giant magnetostrictive material is TbFe 2 (λs = 17353 × 10 −6 ) or SmFe 2 (λs = 1-1560 × 10 −6 ) among Laves type intermetallic compounds represented by ReFe 2. [Clark (1974): Giant magnetostrictive material, published by Nikkan Kogyo Shimbun, Ltd.], which has the largest saturated magnetostriction value. If only the magnitude of magnetism is observed, a large magnetostriction (λs˜ ± 4000 × 10 −6 ) is obtained with a single crystal of Dy or Tb at a low temperature of 200 K or less. Examples of these are shown in Table 1.
[0005]
[Table 1]
[0006]
[Problems to be solved by the invention]
The conventional magnetostrictive material has a problem that the magnetostriction is below the liquid nitrogen temperature even when the magnetostriction is large, the actual magnetostriction is small, and the magnetostriction is anisotropic. There are problems subject to restrictions, and high-performance magnetostrictive materials that can solve these problems are expected.
[0007]
The present invention has been made in consideration of such problems, and exhibits a metamagnetic transition that has isotropic magnetostriction and has a large magnetostriction that exceeds the conventional magnetostriction effect near room temperature. An object of the present invention is to provide a magnetic material.
[0008]
[Means for Solving the Problems]
The present invention comprises the following items.
(1) General formula: La (Fe 1-x A x ) 13- δ D q (where A is at least one element of Al, Si, Ga, Ge and Sn, D is at least of hydrogen and nitrogen) One element, x, δ, q is a magnetism that exhibits a metamagnetic transition having a composition represented by atomic ratios 0.05 ≦ x ≦ 0.2, −1 ≦ δ ≦ 1, 0 <q <2) body.
[0009]
(2) General formula: La (Fe 1-x A xy TM y) 13- δ D q ( although, A is excluding Al, Si, Ga, Ge, at least one element of Sn, TM is a Fe transition At least one element of metal elements, D is hydrogen, at least one element of nitrogen, x, y, δ, and q are atomic ratios 0.05 ≦ x ≦ 0.2, 0 <y <0. 1. A magnetic substance that exhibits a metamagnetic transition having a composition represented by 1, −1 ≦ δ ≦ 1, 0 <q <2).
[0010]
(3) General formula: La 1-z RE z (Fe 1-x A x ) 13- δ D q (where A is at least one element of Al, Si, Ga, Ge, Sn, RE is La At least one element among rare earth elements excluding hydrogen, D is at least one element among hydrogen and nitrogen, and x, z, δ, and q are atomic ratios 0.05 ≦ x ≦ 0.2, 0 <z ≦ A magnetic material that exhibits a metamagnetic transition having a composition represented by 0.1, −1 ≦ δ ≦ 1, 0 <q <2).
[0011]
(4) General formula: La 1-z RE z (Fe 1-x A xy TM y ) 13- δ D q (where A is at least one element of Al, Si, Ga, Ge, Sn, TM Is at least one element among transition metal elements excluding Fe, RE is at least one element among rare earth elements excluding La, D is at least one element among hydrogen and nitrogen, x, y, z, δ , Q are atomic ratios 0.05 ≦ x ≦ 0.2, 0 <y <0.1, x> y, 0 <z ≦ 0.1, −1 ≦ δ ≦ 1, 0 <q <2). A magnetic substance that exhibits a metamagnetic transition having the composition shown.
[0012]
(5) the general formula: La (Fe 1-ab Si a C o b) 13 D q ( although, D is hydrogen, at least one element of nitrogen, 0.10 ≦ a ≦ 0.16,0 <b A magnetic substance that exhibits a metamagnetic transition having a composition represented by ≦ 0.08 and 0 <q <2).
[0013]
(6) The magnetic material that exhibits the metamagnetic transition according to (2) or (4), wherein TM is at least one element selected from Co, Ni, and Cu.
[0014]
R E is Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, said at least one element of Lu (3) or (4) A magnetic substance that exhibits the described metamagnetic transition .
[0015]
( 7 ) The magnetic substance that exhibits a metamagnetic transition according to any one of (1) to ( 6 ) above, containing 10% by atom or less and inevitable impurities.
[0016]
The magnetic body that exhibits the metamagnetic transition according to any one of (1) to (7), wherein 90% or more by volume is a cubic NaZn 13 type intermetallic compound .
[0017]
Regarding La (Fe 1-x A x ) 13 that is the basis of the material of the present invention, La is taken in BCC by Fe 1-x A x constituting the icosahedron, and when A = Si, the amount of Si It is known that the magnetic transition temperature Tc (Curie temperature), T N (Nail temperature), and magnetization Ms change by changing (x) [K. H. J. et al. Buschow et al., Journal of Magnetics and Magnetic Materials 36 (1983) 190-296].
[0018]
As a result of detailed investigations on this material, the present inventors have determined that the element of A, which is a substitution element for Fe, is at least one of Si, Al, Ga, Ge, and Zn, and the amount of x is changed. , X is a small composition, and it has been found that a metamagnetic transition from antiferromagnetism to ferromagnetism occurs at a low temperature, and the saturation magnetostriction (λs) exceeds 5000 × 10 −6 due to the metamagnetic transition. It turns out that it is obtained. Here, the metamagnetic transition is a phenomenon that changes to a ferromagnetic material by applying a magnetic field to an antiferromagnetic or paramagnetic state.
[0019]
This material, while the Laves-type magnetostrictive material such as a conventional TbFe 2 has stretch at right angles and parallel magnitude of magnetostriction to the magnetic field direction is opposite anisotropic and (opposite sign), La (Fe 1- xA x ) 13 extends in all directions by applying a magnetic field. In other words, the volume is increased by applying a magnetic field, and the magnetostrictive effect is completely different from that of the conventional giant magnetostrictive material. As a result of studying the composition of this material, the amount of substitution of the element A and Co as the substitution element of Fe, and the substitution amount of the rare earth element as the substitution element of La, it is possible to obtain a material exhibiting a large magnetostriction near room temperature. [JP 2000-54086]. However, in order to develop magnetostriction near room temperature, the composition is strictly controlled, and careful attention is required for the material preparation method and preparation method.
[0020]
The inventors of the present invention have focused on the crystal structure of the material and attempted to control the structure in order to easily develop the giant magnetostrictive effect above room temperature. Tc is lowered by applying pressure to La (Fe 1-x Si x ) 13 . In La (Fe 1-x Si x ) 13 , the magnetic transition temperature rises as the amount of Si increases [JP 2000-54086].
[0021]
This is because when Fe in Fe 1-x A x constituting the icosahedron as shown in FIG. 1 is replaced by Si, the average distance between Fe and Fe increases and Tc increases. Conversely, it has also been found that Tc is reduced by applying pressure to La (Fe 1-x Si x ) 13 .
[0022]
Against this background, the present inventors added interstitial elements to the material, and controlled, in other words, the Fe—Fe interaction of La (Fe 1-x Si x ) 13 without changing the crystal structure. For example, the magnetic transition temperature was controlled.
[0023]
FIG. 2 is a diagram showing the temperature dependence and magnetic field dependence of the magnetization M and strain ΔL / L of La (Fe 0.88 Si 0.12 ) 13 . As La (Fe 0.88 Si 0.12 ) 13 increases in temperature, the magnetization decreases at Tc = 195K, changes from a ferromagnetic material to a paramagnetic material, and strain ΔL / L also decreases at Tc = 195K. The magnetization at 200 K near Tc = 195 K is a paramagnetic material, but exhibits a metamagnetic transition that changes to a ferromagnetic material when a magnetic field is applied, and the strain ΔL / L increases accordingly. Thus, the strain ΔL / L of La (Fe 0.88 Si 0.12 ) 13 shows a good correlation with the magnetization M. Applying a magnetic field to paramagnetic La (Fe 0.88 Si 0.12 ) 13 directly under Tc causes a phase change (metamagnetic transition) from paramagnetic to ferromagnetic, resulting in an increase in lattice constant and volume. This is the magnetostrictive effect of the material. As described above, this material is characterized not only by causing a large volume change by applying a magnetic field, but also by a temperature change in the vicinity of Tc.
[0024]
FIG. 3 shows an X-ray diffraction pattern when hydrogen is occluded in La (Fe 0.88 Si 0.12 ) 13 . The bottom is an X-ray diffraction line of NaZn 13 type, but La (Fe 0.88 Si 0.12 ) 13 and La (Fe 0.88 Si 0.12 ) 13 H 1.6 both show NaZn 13 type and occlude hydrogen. By doing so, it is understood that each diffraction line is shifted to the low angle side, and the lattice constant is increased as a whole. The result of the thermal expansion measurement of this material is shown in FIG. The thermal expansion ΔL / L shows a large decrease in Tc when the temperature is increased. La (Fe 0.88 Si 0.12 ) 13 has a Tc of 190 K, whereas La (Fe 0.88 Si 0.12 ) 13 H 1.6 has a Tc = It greatly exceeds 333K and room temperature (300K). Accordingly, it can be said that the large magnetostriction effect near Tc as shown in FIG. 4 shows a large magnetostriction effect at 50 ° C. (333 K) in the case of La (Fe 0.88 Si 0.12 ) 13 H 1.6 . Furthermore, as shown in FIG. 5, Tc can be lowered by reducing the hydrogen storage amount, and therefore a large magnetostriction effect can be exhibited at any temperature below Tc. At this time, hydrogen is coordinated in the middle of Fe I -Fe I in the NaZn 13 unit cell of FIG.
[0025]
FIG. 6 shows the magnetic transition temperature (Curie temperature) and the lattice constant at room temperature when the hydrogen storage amount of La (Fe 0.88 Si 0.12 ) 13 H q is changed. By changing the amount of hydrogen, Tc can be greatly changed from 190K (−83 ° C.) to 340K (67 ° C.). At this time, the lattice constant at room temperature increases due to the increase in the hydrogen storage amount, and the Curie temperature Tc increases accordingly. When Tc exceeds room temperature, La (Fe 0.88 Si 0.12 ) 13 H q changes from ferromagnetic to paramagnetic at room temperature, so that the lattice constant increases discontinuously.
[0026]
FIG. 7 is a magnetization curve at La (Fe 0.88 Si 0.12 ) 13 H 1.6 (Tc = 333 K) at each temperature (330, 336, 338, 342 K), and is paramagnetic and has no magnetization above Tc. When a magnetic field is applied, magnetization appears and large magnetostriction occurs. As the Tc increases, a high magnetic field is required to generate the magnetostriction effect, and this material is used in the range of (Tc-5) K to (Tc + 10) K to generate a large magnetostriction with high sensitivity. Is desirable. It is preferable to use at Tc ± 5K.
[0027]
In the present invention, the element A as a substitution element for Fe is at least one of Si, Al, Ga, Ge, and Zn, and the ratio of Fe to A increases as the ratio of A increases. In addition, the saturation magnetization becomes small. In La (Fe 1-x A x ) 13 , if x is generally less than 0.05, the NaZn 13 type crystal structure cannot be maintained, and there is no metamagnetic transition that exhibits magnetostriction. On the other hand, when x exceeds 0.3, the ferromagnetic state becomes stable, and the metamagnetic transition that similarly exhibits magnetostriction is not recognized. Therefore, in the present invention, 0.05 ≦ x ≦ 0.2 is set as a preferable range. By changing the amount of TM (Co, Ni, Cu) in claim 2, etc., the number of 3d electrons of Fe carrying magnetism changes, and there is an effect of changing the magnetic transition temperature Tc and the strength of magnetization (Ms). The composition of y at this time is preferably changed in the range of 0 ≦ y <0.1. When y is 0.1 or more, the magnetic property of Fe itself is affected, and therefore a metamagnetic transition that exhibits magnetostriction occurs. It is not suitable. In particular, when TM is Co, the composition of the substitution element Co is changed to change the number of 3d electrons of Fe, which plays a role in magnetism, and has an effect of changing the magnetic transition temperatures Tc and TN and the strength of magnetization. At this time, the composition (y) of Co is preferably changed in the range of 0 <y ≦ 0.08, and if y exceeds 0.08, it influences the magnetism of Fe itself, so that it exhibits magnetostriction. Magnetic transition does not occur and is not suitable. Preferably, the composition of Co is 0.04 ≦ y ≦ 0.06, which is effective by increasing the magnetic transition temperature Tc and obtaining the magnetostriction effect near room temperature.
[0028]
Further, in claims 3 and 4, a part of La is replaced with another rare earth element (Nd, Gd, etc.), so that the saturation magnetic field is reduced. The upper limit of the substitution amount (z) is 0.1. When z exceeds 0.1, RE 2 Fe 17 becomes more stable than a NaZn 13 type compound structure, and metamagnetic transition due to the NaZn 13 structure does not occur, resulting in no giant magnetostriction.
[0029]
The effect of increasing the magnetic transition temperature by changing the interaction of the Fe-Fe alloy by allowing (H, N) to penetrate into the NaZn 13 type compound structure in claims 1, 2, 3, 4, and 5. There is. At this time, if the amount of hydrogen is q ≧ 2, the NaZn 13 type crystal structure cannot be maintained, and the metamagnetic transition that exhibits magnetostriction is lost. On the other hand, if the amount of nitrogen is q> 1.6 or more, the NaZn 13 type crystal structure cannot be maintained, and there is no metamagnetic transition that exhibits magnetostriction. As a result, giant magnetostriction cannot be obtained. In the present invention, 10 atomic% of inevitable impurities may be included.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the present invention will be described below. A material having the composition shown in Table 2 was prepared by arc melting, and a sample heat-treated at 1050 ° C. for 168 hours in a vacuum was cut out with a diamond cutter. Magnetization characteristics and thermomagnetic characteristics were measured using SQUID (manufactured by Quantum Design), and magnetostriction was measured in a superconducting magnet from 4.2 K to 373 K using the capacitance method. The sample for magnetization, thermomagnetism measurement, and magnetostriction measurement was cut into 2 mm × 2 mm × 2 mm and used.
[0031]
As a result, the composition shown in Table 2 has a metamagnetic transition temperature in this case (250K-400K) in the temperature range from near room temperature to 100 ° C. In other words, it exhibits a very large magnetostriction characteristic.
[0032]
[Table 2]
[0033]
【The invention's effect】
As described above, the magnetic material exhibiting the metamagnetic transition of the present invention has isotropic and extremely large magnetostriction characteristics at room temperature or higher as compared with the characteristics of conventional materials. As a result, it has extremely excellent characteristics as a constituent material for a micro displacement control drive unit on the order of μm, a vibrator for generating a strong sound wave, a sensor, and the like.
[Brief description of the drawings]
FIG. 1 shows a NaZn 13 type crystal structure La (FeAl, Si) 13 .
FIG. 2 is a graph showing temperature dependence and magnetic field dependence of magnetization M and strain amount ΔL / L of La (Fe 0.88 Si 0.12 ) 13 .
FIG. 3 shows an X-ray diffraction pattern of La (Fe 0.88 Si 0.12 ) 13 H q (q = 0.0, 1.6).
FIG. 4 is a graph showing temperature dependency of strain ΔL / L of La (Fe 0.88 Si 0.12 ) 13 H q (q = 0.0, 1.6).
FIG. 5 is a graph showing a change in Tc when hydrogen of La (Fe 0.88 Si 0.12 ) 13 H 1.6 is released.
FIG. 6 shows the Curie temperature (Tc) of La (Fe 0.88 Si 0.12 ) 13 H q and the lattice constant at room temperature.
FIG. 7 shows magnetization curves of La (Fe 0.88 Si 0.12 ) 13 H 1.6 (Tc = 333 K) at each temperature (330, 336, 338, 342 K).
Claims (7)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000268192A JP4471249B2 (en) | 2000-09-05 | 2000-09-05 | Magnetic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000268192A JP4471249B2 (en) | 2000-09-05 | 2000-09-05 | Magnetic material |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2002069596A JP2002069596A (en) | 2002-03-08 |
| JP2002069596A5 JP2002069596A5 (en) | 2007-08-16 |
| JP4471249B2 true JP4471249B2 (en) | 2010-06-02 |
Family
ID=18755000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000268192A Expired - Fee Related JP4471249B2 (en) | 2000-09-05 | 2000-09-05 | Magnetic material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4471249B2 (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004005842A1 (en) * | 2002-07-05 | 2004-01-15 | Matsushita Electric Industrial Co., Ltd. | Reader and authentication device including the same |
| US7186303B2 (en) | 2002-08-21 | 2007-03-06 | Neomax Co., Ltd. | Magnetic alloy material and method of making the magnetic alloy material |
| JP3630164B2 (en) * | 2002-08-21 | 2005-03-16 | 株式会社Ｎｅｏｍａｘ | Magnetic alloy material and method for producing the same |
| JP3947066B2 (en) * | 2002-09-05 | 2007-07-18 | 株式会社Ｎｅｏｍａｘ | Magnetic alloy material |
| US7695574B2 (en) | 2002-10-25 | 2010-04-13 | Showda Denko K.K. | Alloy containing rare earth element, production method thereof, magnetostrictive device, and magnetic refrigerant material |
| JP4399771B2 (en) * | 2003-10-08 | 2010-01-20 | 日立金属株式会社 | Magnetic particle and method for producing the same, and magnetic particle unit |
| JP4218032B2 (en) * | 2004-02-13 | 2009-02-04 | 日立金属株式会社 | Magnetic alloy and method for producing the same |
| JP2006124783A (en) * | 2004-10-29 | 2006-05-18 | Hitachi Metals Ltd | Magnetic grain and method for producing the same |
| US7578892B2 (en) | 2005-03-31 | 2009-08-25 | Hitachi Metals, Ltd. | Magnetic alloy material and method of making the magnetic alloy material |
| EP1867744B1 (en) * | 2005-04-05 | 2012-05-23 | Hitachi Metals, Ltd. | Magnetic alloy and method for producing same |
| KR101088535B1 (en) | 2007-02-12 | 2011-12-05 | 바쿰슈멜체 게엠베하 운트 코. 카게 | Article for magnetic heat exchange and method of manufacturing the same |
| GB2459066B (en) * | 2007-02-12 | 2012-02-15 | Vacuumschmelze Gmbh & Co Kg | Article for magnetic heat exchange and method of manufacturing the same |
| CN101681707B (en) | 2007-12-27 | 2014-04-02 | 真空熔焠有限两合公司 | Composite article with magnetocalorically active material and method for production thereof |
| JP5520306B2 (en) | 2008-10-01 | 2014-06-11 | ヴァキュームシュメルツェ ゲーエムベーハー ウント コンパニー カーゲー | Product having at least one magnetocalorically active phase and method of processing a product having at least one magnetocalorically active phase |
| GB2463931B (en) | 2008-10-01 | 2011-01-12 | Vacuumschmelze Gmbh & Co Kg | Method for producing a magnetic article |
| DE102008054522B4 (en) * | 2008-12-11 | 2013-11-21 | Leibniz-Institut Für Festkörper- Und Werkstoffforschung Dresden E.V. | A method of coating the surface of a magnetic alloy material and such an alloy material |
| US9773591B2 (en) | 2009-05-06 | 2017-09-26 | Vacuumschmelze Gmbh & Co. Kg | Article for magnetic heat exchange and method of fabricating an article for magnetic heat exchange |
| CN101882493B (en) * | 2009-05-08 | 2015-09-09 | 包头稀土研究院 | Magnetic alloy material and manufacture method thereof and magnetic refrigerating system |
| US9895748B2 (en) | 2009-10-14 | 2018-02-20 | Vacuumschmelze & Gmbh & Co. Kg | Article for magnetic heat exchange and method of manufacturing the same |
| GB2482880B (en) | 2010-08-18 | 2014-01-29 | Vacuumschmelze Gmbh & Co Kg | An article for magnetic heat exchange and a method of fabricating a working component for magnetic heat exchange |
-
2000
- 2000-09-05 JP JP2000268192A patent/JP4471249B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2002069596A (en) | 2002-03-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4471249B2 (en) | Magnetic material | |
| JP2002069596A5 (en) | ||
| Takenaka et al. | Magnetovolume effect and negative thermal expansion in Mn3 (Cu1− xGex) N | |
| Yang et al. | Structure and magnetic properties of the MnBi low temperature phase | |
| JP3466481B2 (en) | Giant magnetostrictive material | |
| Clark | Magnetostrictive RFe2 intermetallic compounds | |
| Wang et al. | Characterization of polycrystalline Fe 2 B compound with high saturation magnetization | |
| Takenaka et al. | Magnetostructural correlations in nitrogen-deficient antiperovskite Mn3CuN1-δ | |
| Levin et al. | Reversible spin-flop and irreversible metamagneticlike transitions induced by a magnetic field in the layered Gd 5 Ge 4 antiferromagnet | |
| JP3452210B2 (en) | Manufacturing method of magnetostrictive material | |
| Dai et al. | Magnetism, elasticity, and magnetostriction of FeCoGa alloys | |
| Hu et al. | Anisotropy compensation and magnetostrictive properties in Tbx Dy1− x (Fe0. 9Mn0. 1) 1.93 Laves compounds: Experimental and theoretical analysis | |
| Szymczak | From almost zero magnetostriction to giant magnetostrictive effects: recent results | |
| Zhang et al. | Design of high resistivity light-rare-earth-based PrFe1. 93 magnetostrictive alloys: Si doping and high-pressure annealing | |
| Du et al. | Magnetostriction in twin-free single crystals Tb y Dy 1− y Fe 2 with the addition of aluminum or manganese | |
| US5565830A (en) | Rare earth-cobalt supermagnetostrictive alloy | |
| Hu et al. | Structural, magnetic and magnetostrictive behavior in Nd (Fe1− xCox) 1.9 compounds | |
| Wecker et al. | Magnetic hardening of (Sm, Zr) Fe3 alloys | |
| Wang et al. | Magnetic properties of Sm Fe Ti V alloys | |
| Stern et al. | Fe 3 Pd ferromagnetic shape memory alloys | |
| Shih et al. | The effect of beryllium addition on magnetostriction of the Tb0. 3Dy0. 7Fe2 alloy | |
| EP1399932A1 (en) | Terbium-dysprosium-iron magnetostrictive materials and devices using these materials | |
| JP6930230B2 (en) | Metal-Insulation System Nanogranular Thin Film and Thin Film Magnetic Sensor | |
| Gabay et al. | Effect of Mg content in melt-spun Mn–Bi–Mg–Sb–In alloys on the structure and properties of field-annealed magnets | |
| Boulet et al. | Structural chemistry, magnetic properties and electrical resistivity of the ternary germanides R2RuGe2 (R= Y, La–Nd, Gd–Er) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A711 Effective date: 20050707 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20050707 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070704 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070810 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20090917 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090929 |
|
| RD05 | Notification of revocation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7425 Effective date: 20091117 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20091127 |
|
| RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A681 Effective date: 20091117 |
|
| RD05 | Notification of revocation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7425 Effective date: 20091117 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100108 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100203 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100226 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100226 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130312 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130312 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140312 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |