The spontaneous magnetism of Pb nanoparticles by oxidation
碩士 === 國立中央大學 === 物理研究所 === 98 === Pb nanoparticles were fabricated by the thermal evaporation method. X-ray diffraction patterns were performed to examine particle size and composition. X-ray diffraction patterns showed that the mean particle diameters of pure Pb nanoparticles are 24 nm. No trace o...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2010
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| Online Access: | http://ndltd.ncl.edu.tw/handle/zj7gzy |
| Summary: | 碩士 === 國立中央大學 === 物理研究所 === 98 === Pb nanoparticles were fabricated by the thermal evaporation method. X-ray diffraction patterns were performed to examine particle size and composition. X-ray diffraction patterns showed that the mean particle diameters of pure Pb nanoparticles are 24 nm. No trace of oxidation or other impurity was found.
The M-H curves in difference temperatures of the Pb nanoparticles can be investigated by physical property measurement system. The result of measurement was found that Pb nanoparticles had spin polarization and diamagnetic. The M-H curves of the Pb nanoparticles can be described by the Langevin function plus the diamagnetic term. A series of oxidation dependent experiments produce the oxide compound on surface of the samples. We found that spontaneous magnetism in zero magnetic field. With the increasement of temperature and oxidation, the spontaneous magnetism was enhancement. At first, the ingredients of Pb/PbO that magnetic moment μp would be increased with the thickness of PbO is thickening; when the ingredients of Pb3O4 was appearance, the magnetic moment μp would be weakened. The saturation magnetization Ms in Pb/PbO would be weakened with the PbO is thickening. The saturation magnetization Ms in Pb/PbO/Pb3O4 would be opposite.
A series of oxidation dependent on experiments reveal the influence of oxidation on spontaneous magnetism in core shell of Pb nanoparticles.
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