Magnetoresistance of oblique angle deposited multilayered Co/Cu nanocolumns measured by a scanning tunnelling microscope

Large-Area Nanopillar Arrays by Glancing Angle Deposition with Tailored Magnetic Properties

Ferromagnetic films down to thicknesses of tens of nanometers and composed by polycrystalline Fe and Fe₂O₃ nanopillars are grown in large areas by glancing angle deposition with magnetron sputtering (MS-GLAD). The morphological features of these films strongly depend on the growth conditions. Vertical or tilted nanopillars have been fabricated depending on whether the substrate is kept rotating azimuthally during deposition or not, respectively. The magnetic properties of these nanopillars films, such as hysteresis loops squareness, adjustable switching fields, magnetic anisotropy and coercivity, can be tuned with the specific morphology. In particular, the growth performed through a collimator mask mounted onto a not rotating azimuthally substrate produces almost isolated well-defined tilted nanopillars that exhibit a magnetic hardening. The first-order reversal curves diagrams and micromagnetic simulations revealed that a growth-induced uniaxial anisotropy, associated with an anisotropic surface morphology produced by the glancing angle deposition in the direction perpendicular to the atomic flux, plays an important role in the observed magnetic signatures. These results demonstrate the potential of the MS-GLAD method to fabricate nanostructured films in large area with tailored structural and magnetic properties for technological applications.

Advanced multi-component nanostructures designed by dynamic shadowing growth

Dynamic shadowing growth is a simple and powerful nanofabrication technique that combines oblique angle deposition with substrate manipulation in a thin film deposition system, which mainly utilizes self-shadowing effect to form well-aligned nanorod arrays. Many unique nanostructures have been fabricated or designed by properly programming the substrate motions, deposition sources, deposition rates, and shadowing effects in multi-step shadowing growth processes. The formed nanostructures have found many promising applications such as chemical and biological sensors, energy storages, nanomotors, etc., due to their unique characteristics of well-controlled morphologies, structures, and compositions. This review is focused on the design and fabrication of both compositionally and morphologically complex nanostructure arrays by multilayer and co-deposition shadowing growth techniques, and the emphasis will be put on the design and fabrication of multi-component nanostructures with different morphologies.