The contents of this dissertation are divided into two sections: (1) the preparation and characterization of quaternary rare-earth chalcogenides and oxychalcogenides and (2) the localized surface plasmon resonance (LSPR) spectroscopy of metallic nanoparticles fabricated by nanosphere lithography (NSL). Single crystals of CsTmCoS3, CsYbCoS3, CsHoCoSe3, CsYbCoSe3, and CsYbZnSe3 have been prepared by the reactive flux method and characterized via x-ray diffraction. Magnetic measurements indicate CsHoCoSe3 is a paramagnet, whereas CsYbCoS3 is an anti-ferromagnet. Both CsYbCoS3 and CsYbCoSe3 exhibit optical band gaps in the near infrared region. CsYbZnSe3 exhibits a broad magnetic transition at ~ 10 K and pronounced differences between ZFC and FC data. The magnetic properties of CsYbZnSe3 can be best described by an Ising uniform antiferromagnetic chain model. Single crystals of La5Cu6.33O4S7 and CeMxOS (M = Cu, Ag; x ≈ 0.8), and bulk powder samples of La5Cu6O4S7 and CeAgOS have been prepared and characterized via x-ray diffraction. La5Cu6O4S7 is a p-type metallic electrical conductor, whereas La5Cu6.33O4S7 is a semiconductor. Both La5Cu6O4S7 and La5Cu6.33O4S7 exhibit an optical band gap Eg = 2.0 eV. CeCu0.8OS is a paramagnetic p-type semiconductor with an optical band gap Eg < 0.73 eV. CeAgOS is paramagnetic with an optical band gap Eg = 0.71 eV. The LSPR of Cu and Al nanoparticles fabricated by NSL are examined by UV-vis extinction spectroscopy and electrodynamics theory. The LSPR of the Cu nanoparticles is significantly affected by the presence of copper oxides and the removal of the oxide species yields a dramatic difference in the observed LSPR. Cu displays an intense and narrow LSPR peak that is comparable to Au and Ag when the LSPR λmax > 650 nm. The presence of a thin alumina oxide layer leads to a significant red shift in the Al LSPR λmax. Both from theory and experiment, it was found that the position of the LSPR λmax of Au > Cu > Ag > Al for NSL nanoparticles of similar size and geometry

Last modified

• 08/28/2018

Creator

• George Hanki Chan

DOI

• https://doi.org/10.21985/N2672J

Subject

• Chemistry

Keyword

• Rare-earths
• Nanosphere Lithography
• Crystal Structure
• Magnetic Properties
• Localized Surface Plasmon Resonance
• Optical Properties

Date created

• 2007-12-05

Resource type

• Dissertation

Rights statement

• In Copyright