Surfactant-Assisted Growth of Giant Magnetoresistive Magnetic Multilayers

小行星9731733 本文研究了用直流磁控溅射法制备的具有自旋阀结构的NiO-Co-Cu基“巨”磁阻磁性多层膜。 我们的目标是采用表面活性剂来控制在原子水平上的基本薄膜沉积步骤，以修改界面和薄膜形态的性质。 这种方法应导致在这些层状系统的磁输运性质的结构敏感性的基本理解。 在多层膜的给定层上沉积合适数量的表面活性剂层应改变表面能和界面能之间的平衡。 潜在的表面活性剂物质（Ag、As、Sn、Sb和Pb）是具有大原子体积的软金属，这些性质有利于它们在层上生长期间“浮”出表面，并留下具有不太容易混合的光滑界面的完整层。 表面活性剂辅助的表面形貌的演变相对于表面活性剂的自旋阀研究在不同阶段的薄膜生长原位和非原位（使用扫描隧道显微镜和原子力显微镜）。 表面分离的表面活性剂的监测，通过X射线光电子能谱。 测量了外加磁场下的磁性能、畴结构和壁转变。 由磁性和非磁性薄膜组成的牺牲调制磁性多层膜是研究的热点。 这些系统具有潜在的设备应用程序的磁光存储材料，使用垂直各向异性的多层膜和作为下一代读取头的高密度存储。 ***

9731733 Chopra This is a study of NiO-Co-Cu-based "giant" magnetoresistive magnetic multilayers in spin valve configuration, deposited by dc-magnetron sputtering. The goal is to employ surfactants to control elementary film deposition steps at the atomic level in order to modify the nature of interfaces and film morphology. This approach should result in basic understanding of the structure sensitivity of the magneto- transport properties in these layered systems. Deposition of a suitable number of layers of a surfactant on a given layer of a multilayer should alter the balance between surface and interface energies. The potential surfactant species (Ag, As, Sn, Sb, and Pb) are soft metals having large atomic volumes, properties that favor their "floating" out to the surface during over-layer growth and leaving behind intact layers with smooth interfaces less prone to intermixing. Surfactant assisted evolution of surface topography with respect to surfactant-free spin valves is studied at different stages of film growth in-situ and ex- situ (using scanning tunneling microscopy and atomic force microscopy). Surface segregation of surfactants is monitored by X-ray photoelectron spectroscopy. Magnetic properties, domain structures and wall transition in applied field are measured. %%% Artificially modulated magnetic multilayers comprised of magnetic and non-magnetic films are the subjects of intense research. These systems have potential device applications as magneto-optical storage materials using multilayers with perpendicular anisotropy and as next-generation read-heads for high-density storage. ***