Fabrication of magnetic metal wires by using self-organization on stepped surfaces and its application to three dimensional super lattices

利用阶梯表面自组织制备磁性金属线及其在三维超晶格中的应用

• 批准号: 12450256
• 负责人: TAKANASHI Koki
• 金额: $ 9.66万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450256/
• 关键词: Magnetic film; Magnetic wire; Three dimensional supper raffia; self-organization; atomic step; thin film growth; magnetic properties; nanotechnology; 3次元人工超構造

It is well known that metallic superlattices with artificial one-dimensional periodicity show important properties such as interlayer exchange coupling, magnetoresistance and perpendicular magnetic anisotropy. Giant magnetoresistnace is actually used for reading heads of high density magnetic recording systems. However, the method of multilayering is limited to preparation of one-dimensional periodic structures. It is hoped that a new method to fabricate artificial periodic structures, which could be applied for three-dimensional artificial nanostructures, is developed.In this study, we have studied structures and magnetic properties of magnetic metal wires and films grown at step edges of nonmagnetic underlayers. Additionally, we have investigated on possibility that such a self-organization process is utilized for forming and controlling three dimensional nanostructures. The main result of this study is structural control and enhanced coercivity in FePt alloy films grown on stepped Pt underlayers. The enhanced coercivity is an useful effect, and is explained by domain wall pinning at step edges. For the enhanced coercivity, geometrical effects play an significant role, and the coercivity depends not only on the miscut angle but also the miscut direction of substrates. Results for basic understandings of thin film growth and self-organization process are also obtained. Monatomic layer control is achieved in Co/Ru system, and artificial antiferromagnetic CoRu alloys are prepared. Low-temperature fabrication of L1_0-ordered FePt alloys is successfully performed by the same technique.

众所周知，具有人工一维周期性的金属超晶格具有层间交换耦合、磁阻和垂直磁各向异性等重要性质。巨磁电阻实际上用于高密度磁记录系统的读取头。然而，多层膜的方法仅限于制备一维周期结构。本论文研究了在非磁性衬底台阶边生长的磁性金属丝和磁性薄膜的结构和磁性。此外，我们还研究了这种自组织过程用于形成和控制三维纳米结构的可能性。这项研究的主要结果是在阶梯状铂衬底上生长的FePT合金薄膜的结构控制和矫顽力增强。这种增强的矫顽力是一种有用的效应，可以用台阶边缘的磁化壁钉扎来解释。对于增强的矫直力，几何效应起着重要的作用，并且矫顽力不仅取决于衬底的错切角度，而且还取决于错切的方向。对薄膜生长和自组织过程的基本认识也得到了结果。在Co/Ru体系中实现了单原子层控制，制备了人工反铁磁性CoRu合金。用同样的方法成功地制备了L10有序FePT合金。