Self-assembled Co nanorods in diamond-like carbon thin films synthesized by plasma-assisted magnetron sputtering

We report on self-assembled, high-aspect-ratio nanostructures of Co rods in diamond-like carbon (DLC) thin films synthesized by plasma-assisted magnetron sputtering. Cross-sectional and plan-view transmission electron microscopy investigations show that the nanorods continuously grow vertically to the substrate and have a relatively narrow distributed lateral size. The nanorods in the as-deposited thin films are found to have an ε-Co structure with a high density of defects and are encapsulated by 1–2 nm of an amorphous DLC matrix.