Magneto-dynamic Behavior of Nano-magnetic particle under External Magnetic Field
| Autor: | Jing Wen Huang, 黃靜雯 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 Dynamic properties of magnetic nanoparticles have been intensively studied. For example, magnetic immunoassay has been developed to qualify specific molecules bound to magnetic nanoparticles, which relaxation behavior has been distinguished from bound and unbound ones. The magneto-dynamics is also directly relevant for magnetic hyperthermia, which occurred at the absorption frequencies under electromagnetic radiation. This thesis aims to study the magneto-dynamic behavior of the ferrite nanoparticles under external magnetic field. In this work, a novel resonator structure is designed to characterize the magneto-dynamics of ferrofluid. The ferrite (Fe3O4) nanoparticles can be synthesized from a chemical reaction method, by adjusting ph value in the solution to control particle size ~ 20-30 nm. The average diameter of particle size measured by X-ray diffraction. Further more, the magnetization curve, measured by vibration sample magnetometer, has shown nearly superparamagnetic behavior. By applying external magnetic filed, the impedance spectra are to be measured and analyzed, to investigate magnetic interaction effects in the dynamic response of ferrofluid. In addition, magnetic interaction effects in the dynamic response of ferrofluid explored to an external dc magnetic field are investigated. The analysis of the complex magnetic susceptibility, deduced from the scattering parameter, has being based on the ferromagnetic resonance theory. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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