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Metal oxide nanoparticles, both magnetic and nonmagnetic, have a multitude of applications in gas sensors, catalysts and catalyst supports, airborne trapping agents, biomedicines and drug delivery systems, fuel cells, laser diodes, and magnetic microwaves. Over the past decade, an inexpensive, simple, recyclable, and environmentally friendly large, scale synthesis method for the synthesis of these metal oxide nanoparticles has been sought. Many of the current techniques in use today, while good on the small, laboratory bench scale, suffer from drawbacks that make them unsuitable for the industrial scale. The aminolytic method, developed by Dr. Man Han while working for Dr. Zhang, fits industrial scale-up requirements. The aminolytic method involves a reaction between metal carboxylate(s) and oleylamine in a non-coordinating solvent. This system was shown to produce a range of spinel ferrites. Dr. Lisa Vaughan showed that this method can be recycled multiple times without degrading the quality of the produced nanoparticles. The purpose of this thesis is to test the versatility of the aminolytic method in the production of a wide range of metal oxides as well as various core/shell systems. Chapter 2 explores the effect of precursor carboxylates chain length on the aminolytic synthesis of cobalt ferrite, and manganese ferrite nanoparticles. In Chapter 3, a series of CuxMn1-xFe₂O₄, (x ranges from 0.0 to 0.2), nanoparticles were synthesized via the aminolytic method. This series allows for the investigation of the effects of orbital Jahn-Teller distortion as well as orbital angular momentum on the magnetic properties of this ferrite. The quantum couplings of magnetic ions in spinel ferrites govern their magnetic properties and responses. An understanding of the couplings between these metal ions allows for tailoring magnetic properties to obtain the desired response needed for various applications. Chapter 4 investigates the synthesis of MnO and Mn₃O₄ nanoparticles in pure single phase with high monodispersity. To the best of our knowledge, the range of sizes produced for MnO and Mn₃O₄ is the most extensive, and therefore a magnetic study of these systems shows some intriguing size dependent properties. The final part of this chapter investigates the applicability of the aminolytic method for building a MnO shell on a CoFe₂O₄ core. Chapter 5 explores the synthesis of another metal oxide, ZrO₂ in both the cubic and monoclinic phases with no impurities. The use of the aminolytic method here removes the need for dangerous/expensive precursors or equipment and eliminates the need for extensive high temperature heat treatments that destroy monodispersity which is required for most techniques. The creation of a core/shell system between CoFe₂O₄ and ZrO₂ using the aminolytic method was also tested. This core/shell system adds magnetic manipulation which is especially useful for the recovery of zirconia based photocatalyst. Chapter 6 studies the application of the aminolytic method in the synthesis of yttrium iron garnet (YIG) and yttrium iron perovskite (YIP) nanoparticles. Current synthesis techniques used to produce YIG and YIP nanoparticles often requires high temperatures, sensitive to contamination, which could be eliminated through the use of our method

The syntheses, structures, and magnetic properties of a series of di/trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates were investigated. Treatment of manganese(III)acetylacetonate with KTp* followed by tetra(ethyl)- ammonium cyanide affords [NEt4][(Tp*)MnII(acac)(CN)] (1). Attempts to oxidize 1 with iodine affords {(Tp*)MnII(κ2O-acac-CN)}n (7); a minor complex {[NEt4][(Tp*)MnII(κ2O-acac-3-CN)]2(µ-CN) (8) was also isolated. The manganese(II) complex [NEt4][(Tp*)MnII(κ2O-acac-3-CN)(κ1N -3-NC-acac)] (2) was obtained via treatment of Mn(3-acacCN)3 with KTp* and [NEt4]CN. [NEt4]2[MnII(CN)4] (3) was prepared via treatment of Mn(OTf)2 with excess [NEt4]CN. [NEt4][(Tp*)MnIII(CN)3] (4), is prepared via treatment of 4 with Mn(3-acacCN)3, KTp* and excess [NEt4]CN. [PPN][(Tp*)MnIII(CN)3] (5) is obtained via treatment of [PPN]3[MnII(CN)6] with (Tp*)SnBu2Cl. Combination of 4 with [MnII(bipy)2(OH2)2][OTf]2 afforded a tetranuclear rectangular cluster {MnIII 2MnII 2} (9). At low temperature, {MnIII2NiII2} (10) was prepared via treatment of 4 and [Ni(II)(bipy)2(H2O)2][OTf]2. Treatment of 4 with [CoII(bipy)2(OH2)2][OTf]2 at low temperature failed to give the desired {MnIII2CoII2} complex. Magnetic measurements indicate that 1, 2, and 7 contain high-spin isotropic MnII with no long-range magnetic order observed for 7 (T > 2 K); 4 contains low-spin MnIII that likely adopt an isotropic 3A2 spin ground state. Surprisingly 9 and 10 do not exhibit slow relaxation of the magnetization (for T > 1.8 K) despite the presence of significant molecular anisotropy.

This work includes formulation of mechanically flexible magnetic composites and application to a quarter-wavelength microstrip patch antenna benchmarking structure operating in the lower UHF spectrum (~300-500 MHz) to investigate capability for miniaturization. A key challenge is to introduce sufficiently low magnetic loss for successful application. Particles of NiZn ferrite and BaCo ferrite, also known as Co2Z, were characterized. Flexible magnetic composites comprised of 40 vol% NiZn ferrite or BaCo ferrite particles in a silicone matrix were formulated. Effects of treating the particles with silane in the formulation process were not detectable, but larger particle size showed to increase complex permittivity and complex permeability. By comparing complex permittivity and complex permeability of the composites, BaCo ferrite was selected for the antenna application. Antennas on the developed magnetic composite and pure silicone substrates were electromagnetically modeled in a full-wave FEM EM solver. A prototype of the antenna on the magnetic composite was fabricated. Good agreement between the simulated and measured results was found. Comparison of the antennas on the magnetic composite versus the pure silicone substrate showed miniaturization capability of 2.4X and performance differences of increased bandwidth, reduced Q, and reduced gain. A key finding of this study is that a small amount of permeability (relative permeability ~2.5) can provide relatively substantial capability for miniaturization, while sufficiently low magnetic loss can be introduced for successful application at the targeted operating frequency. The magnetic composite showed the capability to fulfill this balance and to be a feasible option for RFID applications in the lower UHF spectrum.

Thesis (Ph. D.)--McMaster University (Canada), 1990. / Source: Dissertation Abstracts International, Volume: 52-10, Section: B, page: 5290. Supervisor: M.F. Collins.

Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Nie, Shuming; Committee Member: Bao, Gang; Committee Member: Chung, Leland; Committee Member: Murthy, Niren; Committee Member: Prausnitz, Mark.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 227-250). Also available via the Internet.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references (leaves 145-148). Issued in print and online. Available via ProQuest Digital Dissertations.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Jorge Piekarewicz, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (Jan. 19, 2005). Includes bibliographical references.

Thesis (Ph. D.)--Materials Science and Engineering, Georgia Institute of Technology, 2006. / Tannenbaum, Rina, Committee Chair ; Rosario Gerhardt, Committee Member ; Hamid Garmestani, Committee Member ; Karl Jacob, Committee Member Vita. Includes bibliographical references.