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

University Of Florida, Gainesville FL

Investigators

Abstract

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.