Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/17307
標題: CuMn2-xMgxO4(x=0~0.8)奈米線的製備及其磁性的研究
Synthesis and Magnetism of CuMn2-xMgxO4(x=0~0.8) Nanowires
作者: 鄭博謙
Cheng, Po-Chien
關鍵字: 奈米線
nanowire
磁性
自旋相干長度
尖晶石
陽極氧化鋁
magnetism
spin correlation length
spinel
anodic aluminum oxide
出版社: 奈米科學研究所
引用: [1] C. Kittel, Introduction of Solid State Physics, 8th, John Wiley & Sons inc, New York, (1997). [2] H. Luo, T. Klimczuk, L. Muchler, L. Schoop, D. Hirai, M. K. Fuccillo, C. Felser, R. J. Cava, Phys. Rev. B 87, 214510 (2013). [3] Y. Yamasaki, S. Miyasaka, Y. Kaneko, J-P. He, T. Arima, Y. Tokura, Phys. Rev. Lett. 96, 207204 (2006). [4] Q. Geng, X. Zhao, X. Gao, H. Yu, S. Yang, G. Liu, Solar Energy Materials & Solar Cells 105 (2012). [5] G. Lawes, B. Melot, K. Page, C. Ederer, M. A. Hayward, Th. Proffen, R. Seshadri, Phys. Rev. B 74, 024413 (2006). [6] S. Weber, P. Lunkenheimer, R. Fichtl, J. Hemberger, V. Tsurkan, A. Loid, Phys. Rev. Lett. 96, 157202 (2006). [7] T. Furubayashi, H. Suzuki, N. Kobayashi, S. Nagata, Solid State Commun. 131 (2004). [8] Z. Yang, S. Tan, Y. Zhang, Solid State Commun. 115 (2000). [9] A. K. M. Akther Hossain, M. Seki, T. Kawai, H. Tabata, J. Appl. Phys. 96, 1273 (2004). [10] K. Ohgushi, Y. Okimoto, T. Ogasawara, S. Miyasaka, Y. Tokura, J. Phys. Soc. Jpn. 77 (2008) [11] Ch. Kant, J. Deisenhofer, V. Tsurkan, A. Loidl, J. Phys.: Conf. Ser. 200, 032032 (2010). [12] G. Shen, D. M. Jiang, F. Lin, W. Z. Shi, X. M. Ma, S. X. Cao, J. C. Zhang, Physica B 366 (2005). [13] B. D. White, J. A. Souza, C. Chiorescu, J. J. Neumeier, J. L. Cohn, Phys. Rev. B 79, 104427 (2009). [14] O. Tchernyshyov, R. Moessner, S. L. Sondhi, Phys. Rev. Lett. 88, 067203 (2002). [15] E. Pavarini, I. Dasgupta, T. Saha-Dasgupta, O. Jepsen, O. K. Andersen, Phys. Rev. Lett. 87, 047003 (2001). [16] D. P. Shoemaker, R. Seshadri, Phys. Rev. B 82, 214107 (2010). [17] H. Masuda, H. Yamada, M. Satoh, H. Asoh, M. Nakao, T. Tamamura, Appl. Phys. Lett. 71, 19 (1997) [18] 劉如熹, 辛嘉芬, 陳浩銘, 奈米材料的製作與應用-陽極氧化鋁 膜及奈米線製作技術, 全華圖書, (2008). [19] D. Crouse, Yu-Hwa Lo, A. E. Miller, M. Couse, Appl. Phys. Lett. 76, 49 (2000). [20] 汪建民, 材料分析, 中國材料科學學會, (2001). [21] Michael E. Fisher, Michael N. Barber, Phys. Rev. Lett. 28, 1516 (1972).
摘要: 在此研究中,我們使用溶膠凝膠法,配合陽極氧化鋁作為生長奈米線的基板,成功地製備出磁性材料CuMn2-xMgxO4 (x=0、0.2、0.5、0.8)的奈米線陣列。經由場發射掃描式電子顯微鏡與高解析穿透式電子顯微鏡,觀察奈米線的外觀,得到奈米線直徑為65±5nm,長度為44μm。利用電子選區繞射及X-ray粉末繞射結果,獲得樣品結構為面心的立方晶系並且求得晶格常數與鎂離子摻雜濃度之間的關係。使用超導量子干涉元件量測CuMn2-xMgxO4(x=0、0.2、0.5、0.8)奈米線的磁化強度、磁滯曲線,觀察其與塊材的差異。我們發現,塊材與奈米線都呈現鐵磁性,但是尺寸效應導致奈米線的居禮溫度比塊材的小。我們以自旋相干長度的計算來了解尺寸效應對CuMn2-xMgxO4(x=0、0.2、0.5、0.8)的影響。隨著鎂離子的摻雜比例增加使錳離子間的距離會變大,導致錳離子與錳離子之間的耦合能力降低。當鎂離子的摻雜增加會導致樣品的居禮溫度下降,以及自旋相干長度變短。
In our investigation, we use the sol-gel method in coordination with anodic aluminum oxide (AAO) as a substrate to prepare nanowire arrays of CuMn2-xMgxO4(x=0、0.2、0.5、0.8). First, we observe the morphology of nanowries via field emission scanning electron microscope (FE-SEM) and high resolution transmission electron microscope (HR-TEM). The nanowires'' diameter is about 65±5nm, and their length is about 44μm. Second, we use selected area diffraction and X-ray powder diffraction to study the crystal structure and lattice constants. Both bulks and nanowires of CuMn2-xMgxO4(x=0、0.2、0.5、0.8) are ferromagnetism. The speculation of the reduction of Curie temperature for nanowires is due to finite-size effects. The scaling theory ξ(T)=ξ_0 [1-T/(T_C (∞) )]^(-ν)proposed by Fisher et al. was used to describe the finite-size effects in the critical region. With the increasing Mg2+ concentration, the couplings among Mn3+/ Mn4+ ions decrease that results in the decrease of Curie temperature and spin correlation length.
URI: http://hdl.handle.net/11455/17307
其他識別: U0005-0208201316091900
文章連結: http://www.airitilibrary.com/Publication/alDetailedMesh1?DocID=U0005-0208201316091900
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