Synthesis and Characterization of Metallic Nanostructures via Pulsed Laser Induced Dewetting and Electron Beam Lithography

Metallic nanostructures have a wide range of applications from high resolution sensing to cancer treatment. Here, these structures are synthesized via a combination of single metal and bi-metal sputtering, in parallel with pulsed laser induced dewetting (PLiD) and electron beam lithography. PLiD is used to generated arrays of spherical caps that can be controlled by initial thin film geometry, namely the thickness. Electron beam lithography is used to produce higher complexity structures such as coupled meta-atoms. By using metallic elements that possess plasmonic (Au and Ag) and magnetic (Ni and Co) properties, tunability that is a function of size, composition, and chemical morphology can be achieved. In this work we first investigate the PLiD dewetting of a two-component system, Ag-Ni, to observe how the thermodynamic un-mixing behavior interplays with dewetting dynamics. This is done through a combination of fluid dynamic computational modeling (collaboration with NJIT), thermal finite element modeling, and experimental results. In the next chapter, the properties of this material system are studied. Both as deposited thin films, and PLiD particles of varying sizes are fabricated and measured to determine the magneto-plasmonic bi-functionality and tunability of the material system. In the third chapter, the magnetic and plasmonic properties of a second material system, Au-Co, are investigated. In this chapter chemical composition and chemical morphology are added to the tunability parameters. Finally, the fourth chapter investigates the use of electron beam lithography to synthesize ring nanostructures with plasmonic modes that can be excited through both the electric and magnetic components of an incident light source. Imaging of this behavior will be done via excited state electron energy gain and loss spectroscopy.