Graduation Year

2005

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Physics

Major Professor

Sarath Witanachchi, Ph.D.

Committee Member

Pritish Mukherjee, PhD.

Committee Member

George Nolas, PhD.

Keywords

Titanium carbide, Thin films, Ferrous oxide, Drop casting, Nanoparticles

Abstract

This thesis describes a new Laser-Assisted Spray Pyrolysis technique developed to grow nanoparticle coatings with controllable particle sizes. In this method, droplets of a precursor formed by a nebulizer are injected into a growth chamber using SF6 carrier gas. An experimental study and a computational model to investigate the particle size dependence on various growth parameters have been carried out. The results show that heating of 1.5µm droplets of metalorganic precursor in a carrier gas using a CO2 laser resulted in the formation of TiC and Fe3O4 particles with diameters in the range of 50- 60nm. Also the results show that by reducing the concentration of the metal organic precursor the diameter of the deposited particles can be reduced.

In addition, we have investigated the formation of 2-D super lattices of gold nanoparticles on silicon substrate by using a technique called vapor-phase self-assembly, and have used this monolayer as a base coating for growth of TiC coatings with controlled grain sizes. The initial growth of TiC by laser ablation on heated templates indicates preferential nucleation of TiC on Gold Nanoparticles.

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