使用熱蒸鍍法製作錫奈米微粒，以Sn060302表示。以SEM、AFM與X光繞射圖，定出微粒粒徑。從EDS與X光繞射圖分析，錫奈米微粒無明顯氧化物。
3.3nm的錫奈米微粒，Sn060302，觀察到自旋極化現象。本論文近一步壓合奈米微粒，產生交互作用，觀察到自旋極化有明顯的增益現象。在粒子間距在2nm時，飽和磁化強度有最大值。交互作用的系統複雜，以交換能、磁矩-磁矩交互作用為主要影響微粒的自旋極化。具有自旋極化的錫奈米微粒經壓合產生磁化強度增強，剩磁增大，類似於磁疇與交換能的鐵磁性現象。

We selected a gas-evaporation method to product Sn nanoparticles. The sample which was characterized using field emission scanning electron microscope, atomic force microscope observations, and x-ray diffraction measurements didn’t obviously constitute in tin oxides analyzed by energy dispersive spectrometer and x-ray diffraction measurements.
We demonstrate the spin polarization of Sn fine particles, Sn060302, with an average diameter of 3.3nm and furthermore, the enhanced magnetic property of Sn nanoparticles by reducing interparticle separation is studied as well as the maximum saturation magnetization with 2nm separation because of interparticle interaction. The interaction system is complicated. The major fact of enhanced magnetization is related to the exchange energy and dipole-dipole interaction. According to enhanced magnetization, enhanced remnant, alike domain, and exchange integral effect, the ferromagnetic spin polarization of Sn nanoparticles is observed.

[1]M. Tischer, O. Hjortstam, D. Arvanitis, J. Hunter Dunn, F. May, K. Baberschke, J. Trygg, J. M. Wills, B. Johansson, and O. Eriksson, “Enhancement of Orbital Magnetism at Surfaces: Co on Cu(100),” Phys. Rev. Lett. 75 1602 (1995)
[2]T. Koide, H. Miyauchi, J. Okamoto, T. Shidara, A. Fujimori, H. Fukutani, K. Amemiya, H. Takeshita, S. Yuasa, T. Katayama, and Y. Suzuki, “Direct Determination of Interfacial Magnetic Moments with a Magnetic Phase Transitionin Co Nanoclusters on Au(111),” Phys. Rev. Lett. 87 257201 (2001)
[3]H. Hori, T. Teranishi, Y. Nakae, Y. Seino, M. Miyake, S. Yamada, “Anomalous magnetic polarization effect of Pd and Au nano-particles,” Phys. Lett. A 263 406 (1999)
[4]T. Shinohara and T. Sato, “Surface Ferromagnetism of Pd Fine Particles,” Phys. Rev. Lett. 91 197201 (2003)
[5]H. Hori, Y. Yamamoto, T. Iwamoto, T. Miura, T. Teranishi, and M. Miyake, “Diameter dependence of ferromagnetic spin moment in Au nanocrystals,” Phys. Rev. B 69 174411 (2004)
[6]Y. Yamamoto, T. Miura, M. Suzuki, N. Kawamura, H. Miyagawa, T. Nakamura, K. Kobayashi, T. Teranishi, and H. Hori, “Direct Observation of
62
Ferromagnetic Spin Polarization in Gold Nanoparticles,” Phys. Rev. Lett 93, 116801 (2004)
[7] S. Y. Wu, and W. H. Li, “Observation of magnetic anomalous in Ag nanoparticles” (unpublish)
[8]S. L. Lai, J. Y. Guo, V. Petrova, G. Ramanath, and L. H. Allen, “Size-Dependent Melting Properties of Small Tin Particles: Nanocalorimetric Measurements,” Phys. Rev. Lett 77, 99 (1996)
[9]Alexandre A. Shvartsburg and Martin F. Jarrold, “Solid Clusters above the Bulk Melting Point,” Phys. Rev. Lett 85, 2530 (2000)
[10]E. Anno and M. Tanimoto, “Size-dependent change in energy bands of nanoparticles of white tin,” Phys. Rev. B 73, 155430 (2006)
[11]何鈞考，“錫奈米微粒的超導參數與自旋極化”，中央大學碩士
論文(2006)
[12]R. Espiau de Lamaestre and H. Bernas, “Significance of lognormal nanocrystal size distributions,” Phys. Rev. B 73, 125317 (2006)
[13] E. Limpert, W. A. Stahel, and M. Abbt, “Log-normal Distributions across the Sciences: Keys and Clues,” BioScience 51, 341 (2001)
[14]許樹恩，吳泰伯，“X光繞射原理與材料結構分析”，初版，民全書局(1993)
63
[15]王進威，“擬合X光繞射峰形判定奈米微粒粉末的粒徑分佈”，
中央大學碩士論文(2006)
[16]汪建民，“材料分析”，四版，民全書局(2005)
[17]Joseph I. Goldstein, Dale E. Newbury, Patrick Echlin, David C. Joy, A. D. Romig, Jr, Charles E. Lyman, Charles Fiori, and Eric Lifshin “Scanning Electron Microscopy and X-Ray Microanalysis, ” 2nd ed, Plenum Press New York
[18]陳志瑋，“調控鎳奈米微粒粉末的磁化強度”，中央大學碩士論
文(2006)
[19]B. D. Cullity “INTRODUCTION TO MAGNETIC MATERIALS”
[20]S.H. Kilcoyne and R. Cywinski, “Ferritin：a model superparamagnet,” J. Magn. Magn. Mater. 140-144 1466 (1995)
[21]J. G. E. Harris, J. E. Grimaldi, and D. D. Awschalom, “Excess spin and the dynamics of antiferromagnetic ferritin,” Phys. Rev. B 60, 3453 (1999)
[22]M. S. Seehra, V. S. Babu, and A. Manivannan, “Neutron scattering and magnetic studies of ferrihydrite nanoparticles,” Phys. Rev. B 61, 3513 (2000)
[23] Steen Morup and Britt Rosendahl Hansen, “Uniform magnetic excitations in nanoparticles,” Phys. Rev. B 72, 024418 (2005)
64
[24] Paolo Allia, Marco Coisson, Paola Tiberto, Franco Vinai, Marcelo Knobel, M. A. Novak, and W. C. Nunes, “Granular Cu-Co alloys as interacting superparamagnets,” Phys. Rev. B 64, 144420 (1984)
[25]V. Sahni and K.-P. Bohnen, “Exchange charge density at metallic surfaces,” Phys. Rev. B 29, 1045 (1984)
[26]V. Sahni and K.-P. Bohnen, “Image charge at a metal surface,” Phys. Rev. B 31, 7651 (1985)
[27]Manoj K. Harbola and Viraht Sahni, “Sturcture of the Fermi hole at surfaces,” Phys. Rev. B 37, 745 (1988)
[28]Steen Morup and Cathrine Frandsen, “Thermoinduced Magnetization in Nanoparticles of Antiferromagnetic Materials,” Phys. Rev. Lett 92, 217201 (2004)
[29] Dorothy Farrell, Yuhang Cheng, R. Willuam McCallum, Madhur Sachan, and Sara A. Majetich, “Magnetic Interactions of Iron Nanoparticles in Arrays and Dilute Dispersions,” J. Phys. Chem. B 109, 13409 (2005)
[30]D. Farrell, Y. Ding, S. A. Majetich, Cecilia Sanchez-Hanke, and Chi-Chang Kao, “Structural ordering effects in Fe nanoparticle two- and three-dimensional arrays,” J Appl. Phys. 95, 6636 (2004)
[31]Dorothy Farrell, Yuhang Cheng, Yi Ding, Saeki Yamamuro, Cecilia
65
Sanchez-Hanke, Chi-Chang Kao, Sara A. Majetich, “Dipolar interactions and structural coherence in iron nanoparticle arrays,” J. Magn. Magn. Mater. 282, 1 (2004)
[32]C. Petit, A. Taleb, and M. P. Pileni, “Cobalt Nanosized Particles Organized in a 2D Superlattice: Synthesis, Characterization, and Magnetic Properties,” J. Phys. Chem. B 103, 1805 (1999)
[33]V. Russier, “Calculated magnetic properties of two-dimensional arrays of nanoparticles at vanishing temperature,” J Appl. Phys. 89, 1287 (2001)
[34]V. Russier, C. Petit, J. Legrand, and M. P. Pileni, “Collective magnetic properties of cobalt nanocrystals self-assembled in a hexagonal network: Theoretical model supported by experiments,” Phys. Rev. B 62, 3910 (2000)
[35]Jesus Garcia-Otero, Markus Porto, Jose Rivas, and Armin Bunde, “Influence of Dipolar Interaction on Magnetic Properties of Ultrafine Ferromagnetic Particles,” Phys. Rev. Lett 84, 167 (2000)