Magnetic Phenomena in Ultra-thin Films and at Thin-film Interfaces

超薄膜和薄膜界面的磁性现象

• 批准号: 0404962
• 负责人: Arthur Hebard
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0404962&HistoricalAwards=false
• 关键词: Magnetic; Phenomena; Ultra; thin; Films

This condensed matter physics project utilizes two recently developed techniques, which are separate but complementary, to study and characterize magnetism in ultra thin films and at thin-film inter-faces. The first employs a specialized vacuum deposition capability for in situ characterization of magnetotransport in freshly deposited thin films without exposure to air. The second utilizes the deposition of high quality pinhole-free dielectrics to fabricate capacitors with dielectric spacing thin enough (50 A) to assure that the contribution from magnetically aligned spins in the conducting magnetic electrodes will dominate the measured capacitance. These techniques, which are uniquely sensitive to the presence of magnetism within a few angstroms of the surface, will be used to study both elemental (e.g., Mn, Fe, Cr) and novel (e.g., dilute magnetic semiconductors, manganites, ruthenates) materials. If successful, this project will solidify the prospects of adding in situ thin-film studies and magnetocapacitance as new tools not only to in-crease our understanding of magnetism at interfaces and surfaces but also to facilitate the engineering of interfaces for magneotelectronic and nanoscience applications. In pursuing these objectives, undergraduate students, graduate students and postdocs will acquire valuable technical and analytical skills for careers in academic, industrial or government settings. This training will be enhanced by the publication and dissemination of research results in scholarly journals, par-ticipation in scientific conferences, and participation in interdisciplinary collaborations.Magnetism in thin-film nanostructures is strongly dominated by surfaces and interfaces. As the thickness of a thin film decreases, the influence of the interfaces at the film's two surfaces begins to dominate, and magnetic phenomena become intimately affected. This individual investigator award utilizes two recently developed techniques, which are separate but complementary, to study and characterize magnetism in ultra thin films and at thin-film interfaces. The first of these techniques employs a specialized vacuum deposition capability for in situ characterization of the magnetic properties of freshly deposited thin films without exposure to air. The second utilizes the deposition of high quality dielectrics to fabricate capacitors that are sensitive to the presence of magnetically aligned spins at the surface of conducting magnetic electrodes. Novel materials such as ferromagnetic semiconductors will be studied. If successful, this project will solidify the prospects of adding in situ thin-film studies and magnetocapacitance as new tools not only to in-crease our understanding of magnetism at interfaces and surfaces but also to facilitate the engineering of interfaces for magneotelectronic and nanoscience applications. In pursuing these objectives, undergraduate students, graduate students and postdocs will acquire valuable technical and analytical skills for careers in academic, industrial or government settings. This training will be enhanced by participation in interdisciplinary collaborations.

这个凝聚态物理项目利用两种最近开发的技术，这是独立的，但互补的，研究和表征超薄膜和薄膜界面的磁性。第一个采用了专门的真空沉积能力，在原位表征新沉积的薄膜，而不暴露于空气中的磁输运。第二种方法利用高质量无针孔的沉积来制造具有足够薄（50 A）的电介质间隔的电容器，以确保来自导电磁电极中的磁对准自旋的贡献将主导所测量的电容。这些技术对表面几埃内的磁性存在非常敏感，将用于研究两种元素（例如，Mn、Fe、Cr）和新的（例如，稀磁半导体、锰氧化物、碳酸盐）材料。如果成功的话，这个项目将巩固增加原位薄膜研究和磁电容作为新工具的前景，不仅增加我们对界面和表面磁性的理解，而且促进磁电子和纳米科学应用的界面工程。在追求这些目标的过程中，本科生，研究生和博士后将获得学术，工业或政府环境中职业生涯的宝贵技术和分析技能。通过在学术期刊上发表和传播研究成果、参加科学会议和参与跨学科合作，将加强这一培训。薄膜纳米结构中的磁性主要由表面和界面决定。随着薄膜厚度的减小，薄膜两个表面的界面的影响开始占主导地位，磁性现象受到密切影响。这项个人研究奖利用两个最近开发的技术，这是独立的，但互补的，研究和表征超薄膜和薄膜界面的磁性。这些技术中的第一种采用专门的真空沉积能力，用于在不暴露于空气的情况下原位表征新沉积的薄膜的磁性。第二种方法是利用高质量的沉积来制造电容器，该电容器对导电磁电极表面处的磁对准自旋的存在敏感。将研究铁磁半导体等新材料。如果成功的话，这个项目将巩固增加原位薄膜研究和磁电容作为新工具的前景，不仅增加我们对界面和表面磁性的理解，而且促进磁电子和纳米科学应用的界面工程。在追求这些目标的过程中，本科生，研究生和博士后将获得学术，工业或政府环境中职业生涯的宝贵技术和分析技能。这种培训将通过参与跨学科合作得到加强。