Magneto-optical interference effect in metalic thin films with nano-structures

纳米结构金属薄膜的磁光干涉效应

• 批准号: 08555150
• 负责人: OTANI Yoshichika
• 金额: $ 6.78万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08555150/
• 关键词: Magneto-optical effect; Domain structure; Ferromagnetic dots array; Ferromagnetic wires; domain wall nucleation; Magnetoresistance

The purpose of this study is to establish a novel magneto-optical diffraction technique to evaluate magnetic state in a sub-micron scale ferromagnetic substance, and to study the correlation between the magnetic state and the electronic transport properties. For this purpose, systematic studies on the 2 dimensional submicron scale dot and wire arrays were carried out by using a newly constructed magneto-optical diffractometer, a SQUID magnetometer, a high precision resistivity measurement equipment, and a magnetic force microscope. As for magneto-optics, the different orders of the diffracted light due to the array structure was found to accomodate significant magneto-optical Kerr effects. The local magnetic domain structure was successfully evaluated by taking into account the Fourier transforms of the periodical magnetic and array structures. Furthermore the diffracted light in a conical diffraction geometry was found to show Kerr effect, which provided a possible method to obtain magnetic information in the wire without an analyser. The transport experiments for the first time demonstrated that a single domain wall can be trapped in either the submicron wide wire or paired circular dots. A clear change in resistivity was found to appear in association with the domain wall nucleation and annihilation. This new phenomenon can not be explained by considering the conventional anisotropy magnetoresistance. The suppression of weak localization is suggested to be a possible mechanism. The same type of systematical studies were performed on the epitaxial Fe and Co wires, demonstrating that periodical domain walls can be stabilized in the wire. In this case, the modulation of the internal field due to the periodical domain walls are found responsible for the reduction in resistivity, that is the reduction of the surface scattering.

本研究的目的是建立一种新的磁光衍射技术来测量亚微米尺度铁磁物质的磁状态，并研究磁状态与电子输运性质之间的相关性。为此，利用磁光衍射仪、SQUID磁强计、高精度电阻率测量装置和磁力显微镜对二维亚微米尺度点线阵列进行了系统的研究。在磁光方面，由于阵列结构而产生的衍射光的不同阶数可以容纳显著的磁光克尔效应。考虑到周期性的磁场和阵列结构的傅立叶变换的局部磁畴结构成功地评估。此外，还发现锥形衍射结构中的衍射光具有克尔效应，这为在不使用检偏器的情况下获得金属丝中的磁信息提供了一种可能的方法。输运实验首次证明了单畴壁可以被捕获在亚微米宽的线或成对的圆形点中。电阻率的明显变化与畴壁的成核和湮灭有关。这种新现象不能用传统的各向异性磁电阻来解释。弱定位的抑制被认为是一种可能的机制。对外延Fe和Co线进行了相同类型的系统研究，表明周期性畴壁可以稳定在线中。在这种情况下，由于周期性畴壁的内部场的调制被发现负责电阻率的降低，即表面散射的减少。

项目成果

Y.Otani: "Magnetic transport properties of sub-micron ferromagnetic wires" IEEE Trans.Magn.34. 1096-1098 (1998)

Y.Otani：“亚微米铁磁线的磁传输特性”IEEE Trans.Magn.34。

Y.Otani: "Magnetic and transport properties of micron size magnetic particulate arrays fabricated on a 2D superconducting Nb films and sub-micron magnetic wires" Proc.Spring MRS Meeting. 475. 215-225 (1997)

Y.Otani：“在二维超导铌薄膜和亚微米磁线上制造的微米尺寸磁性颗粒阵列的磁性和传输特性”Proc.Spring MRS 会议。

Y.Otani: "Magnetic domain walls and electron transport properties in mesoscopic magnets" Solid State Physics. 33. 113-119 (1998)

Y.Otani：“介观磁体中的磁畴壁和电子传输特性”固体物理学。

Y.Otani: "Magneto-optical Kerr effect in conical diffraction geometry of micron-size Fe_3Si array" IEEE Trans.Magn.(to be published). (1999)

Y.Otani：“微米尺寸 Fe_3Si 阵列的锥形衍射几何中的磁光克尔效应”IEEE Trans.Magn.（待出版）。

Y.Otani: "Magnetization reversal in submicron ferromagnetic dots and antidots arrays" IEEE Trans.Magn.34. 1090-1092 (1998)

Y.Otani：“亚微米铁磁点和反点阵列中的磁化反转”IEEE Trans.Magn.34。