Acquisition of a Custom Molecular Beam Epitaxy System for Metals and Insulators

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9625892 Lederman The considerable recent interest in magnetic thin films and superlattices has been fueled in large part by the potential technological applications of giant magnetoresistance (GMR), exchange anisotropy (EA), and perpendicular anisotropies in metallic ferromagnets. However, numerous topics of interest in this field have not been fully explored, including the magnetic interactions in superlattices composed of alternating metallic and insulating layers, and purely insulating magnetic superlattices. These types of superlattices could further our basic understanding of magnetic interactions and lead to unexpected technologies. The molecular beam epitaxy (MBE) system sponsored by this award is designed to grow and characterize a wide variety of magnetic superlattices, including those composed only of insulators, only of metals, or combinations of insulators and metals. %%% Characterizing the structure of these materials is important because the surface and interface structure in magnetic thin films and superlattices can significantly affect their physical properties. In order to understand these properties, it is crucial to study the surface of these materials as a function of growth parameters, such as film thickness, growth temperature, and growth rate. Structural studies can also aid in distinguishing the structural effects from the intrinsic superlattice and interface effects. This can be done in-situ using surface-sensitive techniques such as reflection high energy electron diffraction (RHEED), low energy electron diffraction (LEED), scanning tunneling microscopy (STM), and x-ray photoelectron spectroscopy (XPS) without contamination from the air. This information will be complemented with ex-situ x-ray diffraction measurements. ***