Development of Observation Method of Fine Magnetic Domains using Spin Polarized Electron Detection Probe

自旋极化电子检测探针精细磁畴观测方法的开发

• 批准号: 07650360
• 负责人: NAKAGAWA Shigeki
• 金额: $ 1.6万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650360/
• 关键词: Spin Polarized Electrons; Tunnelin Electron Microscope; Probe Needle; Spin valve; プローブ; 極微細磁区; フォトリソグラフィー

In this research, it is extremely important to develop the probe needle to detect spin polarization of electrons in the magnetic domains in magnetic materials, such as magnetic thin film media used in magnetic recording system especially in perpendicular magnetic recording system. These probe needle were fabricated using photo lithography technique. Firstly, substrates were coated with photoresist (OFPR) layrs and sputtered-Al films were deposited on it. Micro holes with its diameter around several mum were fabricated in the Al layrs by also photolithography technique. Photoresist under the hole were eliminated by the plasma ashing method using Oxygen mixture plasma. The probe will be formed when the sputtered particles through the hole are deposited on the substrate. We clarified that the relationship between aspect ratio, which defined as the diameter of the hole and the thickness of the photoresist layr, and the probe profiles by using Monte-Carlo simulation technique. Small aspect ratio resulted in the sharp profile of the deposited probe needles. Spin tunneling phenomena is one of the key point of this research, because the probe has to detect the spin polarization of the electrons which comes from the magnetic domains in the objective materials to the probe needle through an tunneling effect. In order to clarify the spin tunneling effect, spin valve devices composed of Ni-Fe/Si_3N_4/Ni-Fe sandwiched layrs with Fe-Mn antiferromagnetic bias layrs. It was succesfully observed the spin tunneling spin valve characteristic in these devices.

在这项研究中，开发探针来检测磁性材料磁域中电子的自旋极化非常重要，例如用于磁记录系统特别是垂直磁记录系统的磁性薄膜介质。这些探针是使用光刻技术制造的。首先，在基板上涂上光刻胶（OFPR）层，并在其上沉积溅射铝膜。同样采用光刻技术在Al层上加工出直径为数μm左右的微孔。通过使用氧气混合等离子体的等离子体灰化方法去除孔下方的光刻胶。当溅射粒子通过孔沉积在基板上时，就会形成探针。我们通过使用蒙特卡罗模拟技术阐明了纵横比（定义为孔的直径和光刻胶层的厚度）与探针轮廓之间的关系。小的纵横比导致沉积的探针具有尖锐的轮廓。自旋隧道现象是这项研究的重点之一，因为探针必须通过隧道效应检测从目标材料的磁畴到探针的电子的自旋极化。为了阐明自旋隧道效应，自旋阀器件由Ni-Fe/Si_3N_4/Ni-Fe夹层和Fe-Mn反铁磁偏置层组成。在这些器件中成功观察到了自旋隧道自旋阀特性。

项目成果

Y.Miyamoto, T.Yoshitani, S.Nakagawa and M.Naoe: "Change of magnetoresistance characteristics and crystal sturcture by ion bombardment to interfaces in [Ni_<81>Fe_<19>/Cu] multilayrs" Journal of Applied Physics. 79 [8]. 6392-6394 (1996)

Y.Miyamoto、T.Yoshitani、S.Nakakawa 和 M.Naoe：“通过离子轰击 [Ni_<81>Fe_<19>/Cu] 多层界面来改变磁阻特性和晶体结构”应用物理学杂志。

Shegeki NAKAGAWA,Yueng LIE and Masahiko NAOE: "Preparation of ferrimagnetic Mn_4N compound films at low substrate temperature by reactive facing targets sputtering" Journal of Applied Physics. 84 (8) (to be published). (1997)

Shegeki NAKAGAWA、Yueng LIE 和 Masahiko NAOE：“通过反应面对靶溅射在低衬底温度下制备亚铁磁 Mn_4N 化合物薄膜”应用物理学杂志。

Shigeki NAKAGAWA,: "Preparation of ferrimagnetic Mn_4N compound films at low substrate temperature by reactive facing targets sputtering" Journal of Applied Physics.84・8. (1997)

Shigeki NAKAGAWA，：“通过反应性靶材溅射在低基底温度下制备亚铁磁Mn_4N化合物薄膜”应用物理杂志，84・8（1997）。

Shigeki NAKAGAWA and Masahiko NAOE: "Control of Soft Magnetism of Co-Zr and Co-Zr-Ta Films for Backlayrs in Perpendicular Magnetic Recording Media" IEICE TRANS.ELECTRON.E78-C [11]. 1557-1561 (1995)

Shigeki NAKAGAWA 和 Masahiko NAOE：“垂直磁记录介质中背层 Co-Zr 和 Co-Zr-Ta 薄膜的软磁性控制”IEICE TRANS.ELECTRON.E78-C [11]。

Shigeki NAKAGAWA: "Preparation of soft magnetic and thermally stable Fe-Co-Ta : N/Ti multilayered films by sputter-deposition" Journal of Applied Physics.84・8. (1997)

Shigeki NAKAGAWA：“通过溅射沉积制备软磁和热稳定的 Fe-Co-Ta : N/Ti 多层膜”《应用物理学杂志》.84・8 (1997)。