| 摘要(英) |
Ni nanoparticles were fabricated by the thermal evaporation method. We control the distance among particles by pressing the loosely packed nanoparticle powder samples, and studying the influence of interparticle interaction on the magnetic characters of Ni nanoparticle.
The blocking temperature of the loosely packed Ni nanoparticle powder sample in applied magnetic field 200 Oe is 200 K, we observe that there is not hysteresis at temperature range 4 K to 300 K. And at applied magnetic field 0.15 T, there is an antiferromagnetic transition at 50 K. The interaction among nanoparticles increases when the compacting density increases. The temperature of antiferromagnetic transition also increases, and there is not hysteresis above the antiferromagnetic transition temperature. Hysteresis is observed below the transition temperature. It means interaction of particles is lager than thermal energy below the transition temperature. Beside, we also observe the hysteresis curve is not symmetry at zero field in compacted samples. When compacting density increases, shift of hysteresis is increases. Compacting density is 60 %, the shift is about 400 Oe. This shift may form by spin glass of surface effect of Ni nanoparticles. As applied magnetic field gets back to zero field, the direction of surface magnetic moment is ordered by original applied magnetic field direction. Ferromagnetic central part of nickel nanoparticles can experience these come from surface magnetic moment effect, and make the hysteresis shift. The shift increases as compacting density increases, it means that surface spin glass layer become heavy as the pressure increases, and saturation magnetism of each different pressure reduces as the pressure increases. While compacting density is 60 %, the saturation magnetism of sample only 50 % of bulk left. |
| 參考文獻 |
第一章
[1]羅吉宗、戴明鳳、林鴻明、鄭振宗、蘇程裕、吳育民著，奈米科技導論，全華科技圖書股 份有限公司
[2]A. Punnoose, H. Magnone, M. S. Seehra, Phys. Rev. B 65, 174420（2001）
[3]郭正次、朝春光著，奈米結構材料科學，全華科技圖書股份有限公司（2004）
[4]Soshin Chikazumi著，張煦、李學養合譯，磁性物理學，聯經出版社（1982）
[5]Nicola A. Spaldin, Magnetic Materials fundamentals and device applications, Cambridge university press（2003）
[6]黃楷熒著，化學還原法生成鎳絲及其反應機制探討，清華大學化學 工程系碩士論文
第二章
[1]羅吉宗、戴明鳳、林鴻明、鄭振宗、蘇程裕、吳育民著，奈米科技導論，全華科技圖書股份有限公司
[2]許樹恩、吳泰伯著，X光繞射原理與材料結構分析，國科會精儀中心 (1993)
第三章
[1]Soshin Chikazumi著，張煦、李學養合譯，磁性物理學（1964）
[2]Stephen Blundell, Magnetism in Condensed Matter, P.170（2003）
[3]B.D. Cullity, Introduction to Magnetic Materials（University of Notre Dame）（1984）
[4]Charles Kittel, Introduction to Solid State Physics -7th ed.（1996）
[5]馮端主編，固態物理學大辭典，建宏出版社（1998）
[6]馮端等著，金屬物理學第四卷 超導電性和磁性，科學出版社（2000）
[7]B.D. Cullity, Introduction to Magnetic Materials（University of Notre Dame）, P.412（1984）
第四章
[1]許樹恩、吳泰伯著，X光繞射原理與材料結構分析，國科會精儀中心 (1993)
[2]C. Kittel, Introduction to Solid State Physics, 7th. edition (Willy, NewYork, 1996), P.443
[3]J. M. D. Coey, Physical Review Latters, volume27, number 17 (1971)
[4]Xavier Batlle and Amilcar Labarta, Journal of Physics D: Applied Physics, 35 R15-R42 (2002)
[5]D. K. Kin et Al., Journal of Magnetism and Magnetic Materials, 225, P.256-P.261(2001)
[6]B.D. Cullity, Introduction to Magnetic Materials（University of Notre Dame）（1984）
第五章
[1]J. Dai, J. Q. Wang, C.Sangregorio, J. Appl. Phy. 87, 10（2000）
[2]F. C. Fonseca, G. F. Goya, R. F. Jardim, Phy. Rev. B, 66, 104406（2002）
[3]H. Wang, T. Zhu, K. Zhao, Phy. Rev. B, 70, 092409（2004）
[4]R. H. Kodama, A.E. Berkowitz, Phy.Rev. B, 59, 9 （1999）
[5]Xavier Batlle and Amilcar Labarta, J. Phys. D:Appl. Phys. 35 R15-R42（2002） |
[Endnote RIS 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
[檢視]
plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
Google bookmarks
del.icio.us
hemidemi
facebook
twitter
google
reddit