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Full-Text Articles in Physics
Two Aspects Of Magnetic Nanoparticle Self-Assembly On Thin-Film Multilayers: Custom Media Properties And Accurate Determination Of Nanoparticle Anisotropy Constant, Sara L. Fitzgerald
Two Aspects Of Magnetic Nanoparticle Self-Assembly On Thin-Film Multilayers: Custom Media Properties And Accurate Determination Of Nanoparticle Anisotropy Constant, Sara L. Fitzgerald
Theses and Dissertations
ZFC/FC moment versus temperature measurements are a common technique to determine magnetic properties of nanoparticles. In this work, I varied both applied field strength and nanoparticle concentration to study resulting changes in blocking temperature, TB, and anisotropy constant, K. TB and K values were obtained using both existing and new analytic methods. Accurate determination of these parameters helps researchers optimize the use of magnetic nanoparticles for a variety of applications, including magnetic heating, drug delivery, and magnetic field-directed self-assembly. For magnetic self-assembly particularly, not only nanoparticle properties, but also the magnetic properties of the substrate alter …
Fabrication Of Metal-Silicon Nanostructures By Reactive Laser Ablation In Liquid, Eric J. Broadhead
Fabrication Of Metal-Silicon Nanostructures By Reactive Laser Ablation In Liquid, Eric J. Broadhead
Theses and Dissertations
Metal-silicon nanostructures are a growing area of research due to their applications in multiple fields such as biosensing and catalysis. In addition, silicon can provide strong support effects to metal nanoparticles while being more cost effective than traditionally used supports, like titania. Traditional wet-chemical methods are capable of synthesizing metal-silicon nanostructures with a variety of composition and nanoparticle shapes, but they often require high temperatures, toxic solvents, strong reducing agents, or need capping agents added to stabilize the nanoparticles. Laser processing is an emerging technique capable of synthesizing metal-silicon composite surfaces that offers a faster, simpler, and greener synthesis route …
Magnetic Polymer Composite As A Thermosensitive Agent For Induced Hyperthermia, Nareg Ohannesian
Magnetic Polymer Composite As A Thermosensitive Agent For Induced Hyperthermia, Nareg Ohannesian
Theses and Dissertations
Polyetheretherketone (PEEK) - magnetite (Fe3O4) blended compounds were produced by high speed vibration milling of PEEK-Fe 3O4 powders exposed to hexane and heated to the melting point (~350 °C) to form the homogeneous magnetic polymer composite, which provided a uniform dispersion of magnetite with low agglomerations in the polymer matrix. Polymer composite with 10 wt.% of magnetite displayed a magnetic saturation of 8 emu/g, tensile strength of 60 MPa and Young’s modulus of 4.4 GPa. Biotoxicity assessment was conducted via in vitro assay. The composite did not induce any adverse reactions, permitting use in medical applications. This study develops analytical …
Nanostructured Organic/Inorganic Semicondutor Photovoltaics: Investigation On Morphology And Optoelectronics Performance, Aruna Wanninayake
Nanostructured Organic/Inorganic Semicondutor Photovoltaics: Investigation On Morphology And Optoelectronics Performance, Aruna Wanninayake
Theses and Dissertations
Organic solar cell is a promising technology because of the versatility of organic materials in terms of tunability of their electrical and optical properties. In addition, their relative insensitivity to film imperfections potentially allows for very low-cost high-throughput roll-to-roll processing. However, the power conversion efficiency of organic solar cell is still limited and needs to be improved in order to be competitive with grid parity. This work is focused on the design and characterization of a new organic/inorganic hybrid device to enhance the efficiency factors of bilayer organic solar cells such as: light absorption, exciton diffusion, exciton dissociation, charge transportation …
Spin And Orbital Moments And Magnetic Order In Fe3o4 Nanoparticle Assemblies, Yanping Cai
Spin And Orbital Moments And Magnetic Order In Fe3o4 Nanoparticle Assemblies, Yanping Cai
Theses and Dissertations
Fe3O4 magnetic nanoparticles of 5 to 11 nm in size were prepared by organic methods. Particle size was analyzed by both X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) techniques. Zero Field Cooling (ZFC) / Field Cooling (FC) and magnetization loop measurements were recorded by VSM, and they confirmed superparamagnetic behavior in the sample. The blocking temperature is found to be in the range of 30 K ~ 170 K. It has a dependence on the particle size. ZFC / FC curves also indicate the presence of magnetic coupling between particles. X-ray Magnetic Circular Dichroism (XMCD) measurements of these nanoparticles …
Theoretical Investigation Of The Structures And Stability Of Gas Phase Neutral And Cationic Tixoy Clusters., Baljeet Kaur
Theoretical Investigation Of The Structures And Stability Of Gas Phase Neutral And Cationic Tixoy Clusters., Baljeet Kaur
Theses and Dissertations
Theoretical investigation of the structure and stability of neutral and cationic TixOy cluster series (where y =2x-1, 2x, 2x+1) have been performed. The lowest lying structures for the neutral clusters are usually found in the singlet state. Generally, in bulk and in the case of the neutral TixOy clusters, the 2x cluster series is relatively more abundant than the 2x-1 and the 2x+1 cluster series. But in the case of cationic TixOy clusters, the 2x-1 series is more abundant. To understand the origin of the stability of the TixO2x-1+ clusters, we use density functional theory within the NRLMOL set of …