MATERIALS SCIENCE AND ENGINEERING

SELF-ORGANIZING LINEAR NANOSTRUCTURES

This study examines the growth mechanisms of self-organizing nanostructures on VSe₂ substrates via thermal evaporation in ultra-high vacuum. Atomic force microscopy and scanning electron microscopy revealed that two distinct nanostructure networks form with the evaporation of copper-nanowires and nanotunnels. A proposed mechanism of formation suggests that electronic interaction between evaporated Cu atoms and the VSe₂ crystalline surface causes the nanowires to propagate, and a resulting cycle of tensile and compressive stresses as the separate nanowire networks propagate leads to the formation of nanotunnels. This suggested mechanism is reinforced by the examination of irregular substrate geometries, such as thin films and structured surfaces. Additionally, the first look at the self-organizing behavior of Ag and Mg on VSe₂ was performed. Due to the decreased ability of Ag atoms to donate electrons, it does not exhibit self-organizational behavior, and only clusters form on the crystal surface.

SEM micrographs of VSe₂ crystal surface after short (left) and long (right) Cu thermal evaporation. The appearance of the surface after a long Cu evaporation shows both nanostructures and mechanical deformation of the VSe₂ surface.