Thesis (Ph.D.) - Cairo University - National Institute of Laser Enhanced Sciences - Department of Laser Application in Environmental Metrology Photochemistry and Agriculture

We report a novel and simple chemical route to produce magnetite (Fe₃O₄) nanoparticles in a size range of 4-50nm. The magnetite particles produced were characterized by .X-ray diffractomer (XRD) was used for structural phase identification. Using TEM Analysis for Investigation and examination of the difference in particle size among the prepared samples. Using FTIR Analysis for Investigation of the spectroscopic characteristics of Fe₃O₄ nanoparticles. Studying of the magnetic properties of Fe3O4nanoparticles by using Vibrating Sample Magnetometry (VSM). Naked gold nanoparticles which were prepared in different solvents of different polarities by laser-induced breakdown of the gold metal plate. The Particle sizes were determined by using (TEM). The surface plasmon bands of the gold nanoparticles depends on both dielectric properties ({u0510}{u221E} and {u0510}m) as well as on {u0510}o dielectric constants and the polarity. Fe3O4 nanoparticles with size ~10 nm have been prepared successfully .To make Fe₃O₄ nanoparticles resistant to surface poisoning a new route is developed for coating Fe₃O₄ nanoparticles with noble metals such as gold as shell. The shell thickness of the core {u2013} shell particles becomes tunable through the adjustment of the ratio of the constituents. Thus, the route yields well -defined core {u2013} shell structures of size from 15 to 57 nm with varying proportion of the noble metal to Fe₃O₄ nanoparticles. The core {u2013} shell structures were characterized by X-Ray diffraction (XRD) ,( TEM) analysis, Using FTIR Analysis for Investigation of the spectroscopic characteristics of the core {u2013} shell particles .Studying of the magnetic properties of Iron oxide nanoparticles by using (VSM)

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