Nanodiskar

Nanodiskar, or nanodisks, are nanoscale disk-shaped particles that appear across a range of material classes, including noble metals, magnetic oxides, semiconductors, and ceramic oxides. They typically have diameters on the order of 5 to 100 nanometers and thicknesses of a few to a few tens of nanometers. The disk geometry imparts anisotropic properties, with physical behavior that often differs between in-plane and out-of-plane directions.

Materials and properties vary by composition. Noble-metal nanodisks (such as gold or silver) exhibit plasmonic resonances that can be tuned by size and aspect ratio, making them useful in sensing and photothermal applications. Magnetic nanodisks (for example iron oxide or cobalt-based systems) can show vortex or single-domain magnetic states, which are of interest for data storage and spintronic devices. Semiconductor nanodisks, including cadmium selenide or other quantum-dot materials, can display quantum-confinement effects and tunable optical emission. Core-shell or alloyed variants provide customized surface chemistry and stability.

Synthesis methods for nanodiskar cover both bottom-up and top-down approaches. Chemical synthesis and templated growth allow control over size, thickness, and crystallinity, often with surface ligands that stabilize dispersion and enable functionalization. Lithographic and physical-deposition techniques can produce highly uniform disks on substrates, suitable for device integration, while self-assembly methods enable organized arrays in solution.

Applications span sensing, imaging, photothermal therapy, catalysis, and data storage. Challenges include achieving precise dimensional control, preventing aggregation, and ensuring biocompatibility or environmental safety for biomedical or ecological uses. See also nanorods, nanoplatelets, and quantum dots for related anisotropic nanostructures.