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Physical Sciences and Mathematics Commons

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Physics Faculty Publications and Presentations

2013

Nanoparticles

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Effects Of Extraneous Surface Charges On The Enhanced Raman Scattering From Metallic Nanoparticles, H. Y. Chung, P. T. Leung, D. P. Tsai Jun 2013

Effects Of Extraneous Surface Charges On The Enhanced Raman Scattering From Metallic Nanoparticles, H. Y. Chung, P. T. Leung, D. P. Tsai

Physics Faculty Publications and Presentations

Motivating by recent experiments on surface enhanced Raman scattering (SERS) from colloidal solutions, we present here a simple model to elucidate the effects of extraneous surface charges on the enhanced Raman signal. The model is based on the well-established Gersten-Nitzan model coupled to the modified Mie scattering theory of Bohren and Hunt in the long wavelength approximation. We further introduce corrections from the modified long wavelength approximation to the Gersten-Nitzan model for the improvement of its accuracy. Our results show that the surface charge will generally lead to a blueshift in the resonance frequency and greater enhancements in the SERS …


Magnetic Properties Of Fe Doped, Co Doped, And Fe+Co Co-Doped Zno, J. J. Beltrán, J. A. Osorio, C. A. Barrero, Charles B. Hanna, A. Punnoose May 2013

Magnetic Properties Of Fe Doped, Co Doped, And Fe+Co Co-Doped Zno, J. J. Beltrán, J. A. Osorio, C. A. Barrero, Charles B. Hanna, A. Punnoose

Physics Faculty Publications and Presentations

The structural, electronic, and magnetic properties of Zn0.95Co0.05O, Zn0.95Fe0.05O, and Zn0.90Fe0.05Co0.05O nanoparticles prepared by a sol-gel method are presented and discussed. X-ray diffraction and optical analysis indicated that high spin Co2+ ions substitute for the Zn2+ ions in tetrahedral sites. 57Fe Mössbauer spectroscopy showed the presence of isolated paramagnetic Fe3+ ions in both Fe doped and Fe+Co co-doped ZnO, however, no evidence of ferromagnetically ordered Fe3+ ions is observed. In the Zn0.95Fe0.05O sample, weak presence of ZnFe …