UC Davis

Nanoscale devices have taken center stage in both academic research and industry, bringing with them the need for fabrication, characterization, and understanding of tunable systems for device applications. Here I will discuss the fabrication, characterization, and future application of magnetic thin film systems, tunable hydrogen adsorption/desorption on transition metal thin films, and electrically tunable superconductivity in thin film YBCO devices. With the advancement of modern nanomagnetics and spintronics, the ability to control and tailor spin textures have become the focus of intense research interest. A spin-polarized low-energy electron microscope (SPLEEM) is used to both fabricate and characterize in-situ certain thin film magnetic systems, enabling studies including observing the nature of magnetic chirality within in-plane magnetized systems, as well as investigating induced perpendicular-magnetic anisotropy as a function of material topography. Similar techniques are used to fabricate and measure transition metal thin film systems and their hydrogen adsorption/desorption properties. Metals such as Ni, Pd, and Cs are added to the thin film surfaces to adjust the hydrogen adsorption/desorption characteristics without significantly affecting the physical or chemical properties of the film. Monolayer to submonolayer thicknesses of these metal overlayers were shown to result in H adsorption enhancement, adjustable H reversibility (adsorption/desorption ratio), H exclusion (adsorption suppression), and H trapping (desorption suppression), enabling a wide range of tunability over how H interacts with a thin film surface.