Ultraschnelle Magnetisierungsprozesse in Mikro- und Nanomagneten

微米和纳米磁体的超快磁化过程

• 批准号: 5372894
• 负责人: Professor Dr. Günther Bayreuther
• 金额: --
• 依托单位: Department of Physics and Astronomy
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5372894?language=en
• 关键词: Ultraschnelle; Magnetisierungsprozesse; Mikro; und; Nanomagneten

The dynamic response of micro- und sub-micrometer-size spinvalve film elements on very fast magnetic field pulses will be studied on a time scale of 20 ps to 100 ns. Field pulses will be created by current pulses through micro strip-lines and alternatively by pumping a Schottky diode with femtosecond laser pulses. Magnetization precession and switching will be observed by measuring the giant magnetoresistance with a fast digital sampling oscilloscope. Mainly samples will be studied containing an epitaxial ferromagnetic Fe1-xCox free layer of high structural perfection grown by molecular beam epitaxy; magnetic anisotropies of these films are controlled in a wide range by variation of thickness and composition thus allowing experiments with well-known values of the parameters entering micromagnetic simulations. The influence of anisotropies, of temperature in relation to the Curie temperature and of exchange coupling to a second ferromagnetic layer will be investigated. In a joint experiment with a second research group the GMR signal will be captured simultaneously with a time-resolved scanning Kerr microscopy image to combine the advantages of these complementary methods.

将在20ps到100 ns的时间尺度上研究微米和亚微米尺寸的SPVELVAL薄膜元件在非常快的磁场脉冲下的动态响应。场脉冲将由通过微带线的电流脉冲产生，或者通过用飞秒激光脉冲泵浦肖特基二极管来产生。通过用快速数字采样示波器测量巨磁电阻，可以观察到磁化进动和开关。主要研究的样品中含有分子束外延生长的具有高度结构完整性的外延铁磁性Fe1-xCOX自由层；这些薄膜的磁各向异性可以通过改变厚度和成分在很大范围内进行控制，从而允许使用已知的参数值进入微磁模拟。将研究各向异性、温度与居里温度的关系以及交换耦合对第二铁磁层的影响。在与第二个研究小组的联合实验中，GMR信号将与时间分辨率扫描克尔显微镜图像同时捕获，以结合这些互补方法的优势。