Development of method of high resolution magnetic imaging by spin polarized scanning tunneling microscope

自旋偏振扫描隧道显微镜高分辨率磁成像方法的发展

基本信息

批准号：
17560280
负责人：
UCHIDA Hironaga
金额：
$ 2.3万
依托单位：
Toyohashi University 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：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560280/
关键词：
Magnetic materials Surface Spin polarization Scanning tunneling microscope Ultra high vacuum スピン偏極走査トンネル顕微鏡磁性材料 STM 状態密度

项目摘要

We developed spin polarized scanning tunneling microscope (SP-STM) in order to investigate magnetic properties on surfaces with high resolution. First, we fabricated an ultra-high vacuum (UHV) system that consists of an analysis chamber and a preparation chamber; the analysis chamber equips an electromagnet with maximum magnetic field of 8 kOe, the STM and a low electron energy diffraction and auger electron spectroscopy (LEED/AES) system. The UHV system is evacuated by mechanical rotary pump, turbo molecular pump, ion pump and titanium sublimation pump; after baking this chamber at temperature of 150 degrees, vacuum pressure of lx10^<-8>0 Pa was obtained. The STM consists of a scanner of a tube piezo ceramics, a piezo motor for course approach, coil springs for anti-vibration, a sample holder and a pre-amplifier for measurement of tunneling current. ASTM tip is exchanged by using a wobble stick. Four STM tips and two samples are stored in a carousel inside the analysis chamber. We developed an STM controller with digital control method. A tunneling current flowing between tip and sample is converted by the pre-amplifier, and the obtained voltage is read by 16 bits AD converter, which is used for digital feedback to control the tip position from the sample. Scanning was achieved by applying triangular voltages to X and Y electrodes of the piezo scanner. For measuring spin polarized information, a rock in amplifier was used to detect AC components of the tunneling current. In order to fabricate sample of magnetic nano-structure for SP-STM measurements, fabrication by AFM anodization was performed on the permalloy Ni_<80>Fe_<20> thin film. In this study we developed the SP-STM. Hereafter, we will use this measurement system to obtain the surface magnetic information in nano-scale.

我们开发了自旋极化扫描隧道显微镜（SP-STM），以研究具有高分辨率的表面上的磁性特性。首先，我们制造了一个由分析室和制备室组成的超高真空（UHV）系统。分析室将电磁体配备8个KOE，STM和低电子能量衍射和螺旋螺旋式电子光谱（LEED/AES）系统的最大磁场。 UHV系统通过机械旋转泵，涡轮分子泵，离子泵和钛升华泵撤离；在150度的温度下烘烤此腔室后，获得了LX10^<-8> 0 PA的真空压力。 STM由管子陶瓷的扫描仪组成，用于课程进近的压电电机，用于抗振动的线圈弹簧，样品支架和用于测量隧道电流的预大剂。通过使用Wobble Stick交换ASTM尖端。四个STM尖端和两个样品存储在分析室内的轮播中。我们开发了一个具有数字控制方法的STM控制器。尖端和样品之间流动的隧道电流由预放大器转换，并且通过16位AD转换器读取所获得的电压，该电压用于数字反馈，以控制样品中的尖端位置。扫描是通过将三角电压施加到压电扫描仪的X和Y电极上的。为了测量自旋极化信息，使用放大器中的岩石来检测隧道电流的交流成分。为了为SP-STM测量构成磁性纳米结构的样品，在Permalloy Ni_ <80> Fe_ <20>薄膜上进行了AFM阳极氧化的制造。在这项研究中，我们开发了SP-STM。此后，我们将使用此测量系统在纳米级中获取表面磁信息。