In Situ Quantitative Measurement of Structural and Magnetic Properties of Nano-Structured Cobalt Films and Wires

小行星9701488 本计画主要探讨以分子束磊晶法（MBE）所制备之Co/Cu/Co三层薄膜及CoOwiresO薄膜之结构与磁性。 Co膜和三层膜分别生长在平坦和相邻（阶梯聚束）硅（111）表面上。 描述这些Co纳米结构的界面粗糙度和混合的参数定量地确定原位从角轮廓测量的衍射光束使用高分辨率，低能量电子衍射补充扫描电子显微镜。 利用表面磁光克尔效应（SMOKE）、铁磁共振和货车der Pauw方法，在原位得到了样品的磁化率、磁各向异性、交换耦合、磁电阻和磁不均匀性。 原子力显微镜和磁力显微镜提供了重要的信息形态和磁畴壁结构。 此外，这些纳米结构的温度依赖性和磁稳定性进行了研究。 界面粗糙度和磁阻和磁交换耦合之间的定量关系及其温度依赖性将允许优化的三层，具有最大的和热稳定的磁阻在非常低的磁场。 这样的材料在用于高密度硬盘驱动器的磁读取头中具有应用。 ***

9701488 Wang This project examines the structure and magnetic properties of epitaxial Co/Cu/Co trilayers and Co OwiresO prepared by molecular beam epitaxy (MBE). The Co and trilayer films are grown on flat and vicinal (step bunched) silicon (111) surfaces, respectively. The parameters describing the interface roughness and mixing of these Co nanostructures are determined quantitatively in situ from the angular profile measurement of diffraction beams using high resolution, low energy electron diffraction complemented with scanning electron microscopy. The coercivity, magnetic anistropy, exchange coupling, magneto resistance, and magnetic inhomogeneity are obtained in situ from the surface magneto-optic Kerr effect (SMOKE), ferromagnetic resonance, and the Van der Pauw method. Atomic force microscopy and magnetic force microscopy provide important information on morphology and magnetic domain wall structures. In addition the temperature dependence and magnetic stability of these nanostructures are studied. %%% The quantitative relationship between interface roughness and magneto resistance and magnetic exchange coupling and their temperature dependence will permit an optimization of the trilayer that has the largest and thermally stable magneto resistance at very low magnetic fields. Such materials have applications in magnetic read heads for ultrahigh density hard disk drives. ***