THEORETICAL STUDY IN NANO-PHYSICS OF MAGNETIC ATOM BRIDGES CONTROLLED BY THE STM TIP MANIPULATIONS - NANO-STRUCTURE, NANO-MAGNETISM

STM 尖端操控控制磁原子桥的纳米物理理论研究 - 纳米结构、纳米磁性

基本信息

批准号：
13650026
负责人：
NAKANISHI Hiroshi
金额：
$ 2.24万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

We investigated the nano-physics : nano-lattice-structure, nano-magnetism, and quantum transport, of the magnetic atom bridges constructed between a tip of a scanning tunneling microscope (STM) and a solid surface with the aid of first-principles calculation based on the density functional theory.We show the origin of a change in the magnetic state induced by the STM-tip manipulation and how the change in the magnetic state affects the electron transport phenomena by use of the Fe atom bridge of the simple structure, the linear chain structure. As a result of total energy calculation, the Fe atom bridge of the linear chain structure is unstable and its lattice is too weak to show the change in the magnetic state. The stable atom bridge is of the zigzag chain structure, whose magnetic state is always high-spin ferromagnetic stateWe searched the stable structure of the atom bridge whose lattice structure is enough strong to show a change in the magnetic state. We have found such a stable … More structure. That is the twisted ladder structure. The Fe atom bridge with a twisted ladder structure is stable enough to undergo changes in its magnetic state via compression in length. We showed that it is possible to control the magnetic state by the STM-tip manipulations.We have also investigated the magnetic properties of magnetic alloy atom bridges. In the case of an Fe_<1-x>Ni_x alloy atom bridge, we have found that the atoms maintain a considerably large magnetic moment (about 3μB for an Fe atom and about 0.9μB for a Ni atom), and that the mean magnetic moment per atom in the atom bridge decreases linearly as x increases. In the case of an Fe_xV_<1-x> alloy atom bridges shows a strong contrast with that of the Fe_<1-x>Ni_x alloy atom bridges, and similarities with the bulk of the corresponding alloy, except for the case of x=1.0. In the Fe_<1-x>V_x alloy atom bridge, a V atom has no magnetic moment, and an Fe atom has a smaller magnetic moment than that in the bulk Fe crystal. The magnetic moment of the Fe atom in the Fe-V alloy atom bridge is strongly reduced by the Fe-V atom mixing. These results give us the atom bridge version of the Pauling-Slater curve.Furthermore, we have determined the spin transport phenomena trough these atom bridges. We think that such a systematic investigation gives us the important and useful information in order to establish a basis for the design and fabrication of the atom bridge related nano-spin-electronics devices. Less

我们研究了纳米物理学：纳米静态结构，纳米 - 磁性和量子传输，在扫描隧穿显微镜（STM）的尖端之间构建的磁原子桥梁（STM）和固体表面，并借助于priventement态度的态度，并借助密度的态度来显示磁性的变化。通过使用简单结构的Fe Atom桥（线性链结构）来影响电子传输现象。由于总能量计算，线性链结构的Fe原子桥不稳定，其晶格太弱，无法显示磁性状态的变化。稳定的原子桥是锯齿形链结构，其磁性始终是高旋转铁磁状态，搜索了原子桥的稳定结构，其晶格结构足以显示出磁性状态的变化。我们发现了如此稳定的……更加结构。那是扭曲的梯子结构。具有扭曲梯子结构的Fe原子桥足够稳定，可以通过压缩长度进行磁性变化。我们表明，可以通过STM-TIP操纵来控制磁态。我们还研究了磁合金原子桥的磁性。在Fe_ <1-x> ni_x合金原子桥的情况下，我们发现原子维持了周到的磁矩（对于Fe原子的3μb，Ni原子约为3μb），并且Ni原子的大约0.9μb），并且原子中的每个原子的平均磁矩随着X的增加而近距离降低。在Fe_xv_ <1-X>合金原子桥的情况下，与Fe_ <1-x> ni_x合金原子桥的形成鲜明对比，除了x = 1.0的情况外，与相应合金的大部分相似。在Fe_ <1-X> V_x合金原子桥中，V原子没有磁矩，而Fe原子的磁矩比大体Fe晶体中的磁矩小。 Fe-V合金原子桥中Fe原子的磁矩通过FE-V原子混合大大降低。这些结果为我们提供了Pauling-Slater曲线的原子桥版本。Furthermore，我们确定了这些原子桥的旋转传输现象。我们认为，这样的系统投资为我们提供了重要而有用的信息，以建立与原子相关的Nano-Spin-Spin-Spin-Electronics-electronics设备的设计和制造的基础。较少的