2001 Fiscal Year Annual Research Report

スピントンネル再生磁気ヘッドの開発

Research Project

Project/Area Number	11792002
Research Institution	Tohoku University
Principal Investigator	宮崎照宣東北大学, 大学院・工学研究科, 教授 (60101151)
Co-Investigator(Kenkyū-buntansha)	熊谷静似ソニー(株), 主任研究員久保田均東北大学, 大学院・工学研究科, 助手 (30261605) 安藤康夫東北大学, 大学院・工学研究科, 助教授 (60250726) 菅原淳一ソニー(株), 研究員中塩栄治ソニー(株), 研究員
Keywords	スピントンネル素子 / 低抵抗 / ラフネス / 結晶配向 / 再生磁気ヘッド / 磁気テープ / フラックスガイド / 再生波形
Research Abstract	計画の最終年度である本年は素子の低抵抗化に対するアプローチを東北大学のグループですすめ,ヘッドの試作をソニーグループで行った. 1.スピントンネル素子の低抵抗化昨年度までに絶縁層の薄膜化に伴い絶縁層に欠陥が生じやすくなり,抵抗の減少とともに,磁気抵抗変化率も減少してしまうことがわかった.そこで,本年度は下部磁性層表面のラフネスを抑制し,その上に均一な絶縁層を作製することを図った.具体的には下部電極中のバッファー層材料をCuからNi-Feに変更した接合,および,下部電極中にあったIr-Mn層を取り除き上部電極中に設けた接合を作製した.その結果,Ni-Feバッファー層とした接合において結晶性が高く周期の長い凹凸が得られた.この構成の接合において0.66nmのAlを酸化した絶縁層の障壁高さは1.9eVの比較的高い値が得られた.従って,欠陥の少ない極薄絶縁層の作製に関する指針が得られた. 2.再生磁気ヘッドの試作 0.8nmのAlを酸化した絶縁層を持つトンネル接合をベースとして微細加工プロセスによりフラックスガイド方式の再生ヘッドを試作した.フラックスガイド上にCu/PtMnを積層し,長距離交換相互作用を用いて単磁区化をはかった.試作したヘッドをヘリカルスキャン方式の磁気テープ再生システムに組み込み,再生波形を得た.長さ0.1μmのフラックスガイドを持つヘッドの出力は1.75mVp-pであり,従来方式のヘッドにくらべ2.4dB高い出力電圧を得た.この結果より,長距離交換相互作用およびフラックスガイドを組み合わせた用いたヘッド構造がスピントンネル再生磁気ヘッドに非常に適していることを実証した.

Research Products
(18 results)

All Other

All Publications (18 results)

[Publications] Masamitsu Hayashi: "Scanning Tunneling Microscopy Observation of the Initial State of Oxidation in Ferromagnetic Tunnel Junctions"Jpn.J.Appl.Phys.. 40. L1317-L1319 (2001)
[Publications] Yasuo Ando: "Local transport properties of ferromagnetic tunnel junctions"J.Magn.Magn.Mater.. 226-230. 924-925 (2001)
[Publications] Junichirou Murai: "Magnon excitation of CoFe/Al-oxide/CoFe ferromagnetic tunnel junctions"J.Magn.Magn.Mater.. 226-230. 922-923 (2001)
[Publications] H.Kyung: "Effect of microstructure on the magnetoresistive properties of NiFe/Co(CoFe)/Al(Ta)-oxide/Co(CoFe) tunnel junctions"J.Appl.Phys.. 89. 2752-2755 (2001)
[Publications] X.F.Han: "Fabrication and magnetoelectrc properties of high-magnetoresistance tunnel junctions"J.Magn.Soc.Jpn.. 25. 707-710 (2001)
[Publications] 林将光: "強磁性トンネル接合のスピン依存局所伝導特性"日本応用磁気学会誌. 25. 759-762 (2001)
[Publications] 矢尾板和也: "プラズマ酸化法による低抵抗強磁性トンネル接合の作製"日本応用磁気学会誌. 25. 771-774 (2001)
[Publications] Andrew C.C.Yu: "High resolution electron microscopy of Al-oxide barriers in magnetic tunnel junctions"Japanese Journal of Applied Physics. 40. 5058-5060 (2001)
[Publications] Andrew C.C.Yu: "Direct observation of domain structure and magnetization reversal of mag-netic thin films using Lorentz transmission electron microscopy"Japanese Journal of Applied Physics. 40. 4891-4895 (2001)
[Publications] Andrew C.C.Yu: "Lorentz transmission electron microscopy and magnetic force microscopy characterization of NiFe/Al-oxide/Co films"Journal of Applied Physics. 91. 780-782 (2002)
[Publications] Andrew C.C.Yu: "Microstructural and magnetic characteristics of IrMn exchange-biased tunnel junction"Journal of Magnetism and Magnetic Materials. (in press).
[Publications] Andrew C.C.Yu: "Effect of Ti seed layer on the magnetization reversal process of Co/NiFe/Al-oxide/NiFe junction films"Journal of Applied Physics. (in press).
[Publications] X.F.Han: "A self-consistent calculation of intrinsic magnetoelectric properties in magrnetic tunnel junctions"J.Magn.Magn.Mater.. 239(in press). (2002)
[Publications] X.F.Han: "Analysis of intricsic magnetoelectric properties in spin-valve-type tunnel junctions with high magnetoresutance and low resistance"Physical Review B. 63. 224404-1-224404-7 (2001)
[Publications] X.F.Han: "A self-consistent calculation and an Anisotropic Wavelength Cutoff Energy of Spin-wave Spectrum in Magnetic Tunnel Junctions"J.Mater.Sci.Technol.. 17. 197-202 (2001)
[Publications] H.Kubota: "Magnetoresistance and Dipole Shift of Ultrasmall Magnetic Tunnel Junctions Characterized by Conducting Atomic Force Microscopy"Japanese Journal of Applied Physics. 41. L180-L182 (2002)
[Publications] Eiji Nakashio: "Longitudinal bias method using a long distance exchange coupling field in TMR junction"Journal of Applied Physics. 89. 7356-7358 (2001)
[Publications] Eiji Nakashio: "Flux guide type tunnel-valve head for tape storage applications"IEEE Transaction on Magnetics. (in press).

2001 Fiscal Year Annual Research Report

スピントンネル再生磁気ヘッドの開発

Principal Investigator

宮崎 照宣 東北大学, 大学院・工学研究科, 教授 (60101151)

Research Products

[Publications] Masamitsu Hayashi: "Scanning Tunneling Microscopy Observation of the Initial State of Oxidation in Ferromagnetic Tunnel Junctions"Jpn.J.Appl.Phys.. 40. L1317-L1319 (2001)

[Publications] Yasuo Ando: "Local transport properties of ferromagnetic tunnel junctions"J.Magn.Magn.Mater.. 226-230. 924-925 (2001)

[Publications] Junichirou Murai: "Magnon excitation of CoFe/Al-oxide/CoFe ferromagnetic tunnel junctions"J.Magn.Magn.Mater.. 226-230. 922-923 (2001)

[Publications] H.Kyung: "Effect of microstructure on the magnetoresistive properties of NiFe/Co(CoFe)/Al(Ta)-oxide/Co(CoFe) tunnel junctions"J.Appl.Phys.. 89. 2752-2755 (2001)

[Publications] X.F.Han: "Fabrication and magnetoelectrc properties of high-magnetoresistance tunnel junctions"J.Magn.Soc.Jpn.. 25. 707-710 (2001)

[Publications] 林将光: "強磁性トンネル接合のスピン依存局所伝導特性"日本応用磁気学会誌. 25. 759-762 (2001)

[Publications] 矢尾板和也: "プラズマ酸化法による低抵抗強磁性トンネル接合の作製"日本応用磁気学会誌. 25. 771-774 (2001)

[Publications] Andrew C.C.Yu: "High resolution electron microscopy of Al-oxide barriers in magnetic tunnel junctions"Japanese Journal of Applied Physics. 40. 5058-5060 (2001)

[Publications] Andrew C.C.Yu: "Direct observation of domain structure and magnetization reversal of mag-netic thin films using Lorentz transmission electron microscopy"Japanese Journal of Applied Physics. 40. 4891-4895 (2001)

[Publications] Andrew C.C.Yu: "Lorentz transmission electron microscopy and magnetic force microscopy characterization of NiFe/Al-oxide/Co films"Journal of Applied Physics. 91. 780-782 (2002)

[Publications] Andrew C.C.Yu: "Microstructural and magnetic characteristics of IrMn exchange-biased tunnel junction"Journal of Magnetism and Magnetic Materials. (in press).

[Publications] Andrew C.C.Yu: "Effect of Ti seed layer on the magnetization reversal process of Co/NiFe/Al-oxide/NiFe junction films"Journal of Applied Physics. (in press).

[Publications] X.F.Han: "A self-consistent calculation of intrinsic magnetoelectric properties in magrnetic tunnel junctions"J.Magn.Magn.Mater.. 239(in press). (2002)

[Publications] X.F.Han: "Analysis of intricsic magnetoelectric properties in spin-valve-type tunnel junctions with high magnetoresutance and low resistance"Physical Review B. 63. 224404-1-224404-7 (2001)

[Publications] X.F.Han: "A self-consistent calculation and an Anisotropic Wavelength Cutoff Energy of Spin-wave Spectrum in Magnetic Tunnel Junctions"J.Mater.Sci.Technol.. 17. 197-202 (2001)

[Publications] H.Kubota: "Magnetoresistance and Dipole Shift of Ultrasmall Magnetic Tunnel Junctions Characterized by Conducting Atomic Force Microscopy"Japanese Journal of Applied Physics. 41. L180-L182 (2002)

[Publications] Eiji Nakashio: "Longitudinal bias method using a long distance exchange coupling field in TMR junction"Journal of Applied Physics. 89. 7356-7358 (2001)

[Publications] Eiji Nakashio: "Flux guide type tunnel-valve head for tape storage applications"IEEE Transaction on Magnetics. (in press).

宮崎照宣東北大学, 大学院・工学研究科, 教授 (60101151)