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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/37728完整後設資料紀錄
| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 張慶瑞(Ching-Ray Chang) | |
| dc.contributor.author | Yi-Cheng Huang | en |
| dc.contributor.author | 黃意誠 | zh_TW |
| dc.date.accessioned | 2021-06-13T15:40:42Z | - |
| dc.date.available | 2012-08-12 | |
| dc.date.copyright | 2011-08-12 | |
| dc.date.issued | 2011 | |
| dc.date.submitted | 2011-08-10 | |
| dc.identifier.citation | [1] Stuart S. P. Parkin, Masamitsu Hayashi, and Luc Thomas, “Magnetic domain-wall
racetrack memory,” Science, vol. 320, no. 5873, pp. 190–194, 2008. [2] S. Krause, G. Herzog, T. Stapelfeldt, L. Berbil-Bautista, M. Bode, E. Y. Vedmedenko, and R. Wiesendanger, “Magnetization reversal of nanoscale islands: How size and shape affect the arrhenius prefactor,” Phys. Rev. Lett., vol. 103, no. 12, pp. 127202, Sep 2009. [3] D. A. Allwood, G. Xiong, C. C. Faulkner, D. Atkinson, D. Petit, and R. P. Cowburn, “Magnetic domain-wall logic,” Science, vol. 309, no. 5741, pp. 1688–1692, 2005. [4] Geoffrey S. D. Beach, Corneliu Nistor, Carl Knutson, Maxim Tsoi, and James L. Erskine, “Dynamics of field-driven domain-wall propagation in ferromagnetic nanowires,” Nat Mater, vol. 4, no. 10, pp. 741–744, Oct. 2005. [5] Del Atkinson, Dan A. Allwood, Gang Xiong, Michael D. Cooke, Colm C. Faulkner, and Russell P. Cowburn, “Magnetic domain-wall dynamics in a submicrometre ferromagnetic structure,” Nat Mater, vol. 2, no. 2, pp. 85–87, Feb. 2003. [6] O. A. Tretiakov, D. Clarke, Gia-Wei Chern, Ya. B. Bazaliy, and O. Tchernyshyov, “Dynamics of domain walls in magnetic nanostrips,” Phys. Rev. Lett., vol. 100, no. 12, pp. 127204, Mar 2008. [7] Mi-Young Im, Lars Bocklage, Peter Fischer, and Guido Meier, “Direct observation of stochastic domain-wall depinning in magnetic nanowires,” Phys. Rev. Lett., vol. 102, no. 14, pp. 147204, Apr 2009. 37 [8] Jos’e L. Prieto, Manuel Mu˜noz, and Eduardo Mart’ınez, “Structural characterization of magnetic nanostripes by fast domain wall injection,” Phys. Rev. B, vol. 83, no. 10, pp. 104425, Mar 2011. [9] Sang-Koog Kim, Youn-Seok Choi, Ki-Suk Lee, Konstantin Y. Guslienko, and Dae- Eun Jeong, “Electric-current-driven vortex-core reversal in soft magnetic nanodots,” Applied Physics Letters, vol. 91, no. 8, pp. 082506, 2007. [10] Sang-Koog Kim, Ki-Suk Lee, Young-Sang Yu, and Youn-Seok Choi, “Reliable low-power control of ultrafast vortex-core switching with the selectivity in an array of vortex states by in-plane circular-rotational magnetic fields and spin-polarized currents,” Applied Physics Letters, vol. 92, no. 2, pp. 022509, 2008. [11] Youn-Seok Choi, Myoung-Woo Yoo, Ki-Suk Lee, Young-Sang Yu, Hyunsung Jung, and Sang-Koog Kim, “Out-of-plane current controlled switching of the fourfold degenerate state of a magnetic vortex in soft magnetic nanodots,” Applied Physics Letters, vol. 96, no. 7, pp. 072507, 2010. [12] Ki-Suk Lee and Sang-Koog Kim, “Two circular-rotational eigenmodes and their giant resonance asymmetry in vortex gyrotropic motions in soft magnetic nanodots,” Phys. Rev. B, vol. 78, no. 1, pp. 014405, Jul 2008. [13] Youn-Seok Choi, Ki-Suk Lee, and Sang-Koog Kim, “Quantitative understanding of magnetic vortex oscillations driven by spin-polarized out-of-plane dc current: Analytical and micromagnetic numerical study,” Phys. Rev. B, vol. 79, no. 18, pp. 184424, May 2009. 38 [14] C. T. Boone, J. A. Katine, M. Carey, J. R. Childress, X. Cheng, and I. N. Krivorotov, “Rapid domain wall motion in permalloy nanowires excited by a spin-polarized current applied perpendicular to the nanowire,” Phys. Rev. Lett., vol. 104, no. 9, pp. 097203, Mar 2010. [15] C. T. Boone and I. N. Krivorotov, “Magnetic domain wall pumping by spin transfer torque,” Phys. Rev. Lett., vol. 104, no. 16, pp. 167205, Apr 2010. [16] A. V. Khvalkovskiy, K. A. Zvezdin, Ya. V. Gorbunov, V. Cros, J. Grollier, A. Fert, and A. K. Zvezdin, “High domain wall velocities due to spin currents perpendicular to the plane,” Phys. Rev. Lett., vol. 102, no. 6, pp. 067206, Feb 2009. [17] Z. Li and S. Zhang, “Domain-wall dynamics and spin-wave excitations with spintransfer torques,” Phys. Rev. Lett., vol. 92, no. 20, pp. 207203, May 2004. [18] S. Zhang and Z. Li, “Roles of nonequilibrium conduction electrons on the magnetization dynamics of ferromagnets,” Phys. Rev. Lett., vol. 93, no. 12, pp. 127204, Sep 2004. [19] R.Wieser, E. Y. Vedmedenko, P.Weinberger, and R.Wiesendanger, “Current-driven domain wall motion in cylindrical nanowires,” Phys. Rev. B, vol. 82, no. 14, pp. 144430, Oct 2010. [20] Matteo Franchin, Thomas Fischbacher, Giuliano Bordignon, Peter de Groot, and Hans Fangohr, “Current driven dynamics of domain walls constrained in ferromagnetic nanopillars,” Phys. Rev. B, vol. 78, no. 5, pp. 054447, Aug 2008. 39 [21] J. He, Z. Li, and S. Zhang, “Current-driven vortex domain wall dynamics by micromagnetic simulations,” Phys. Rev. B, vol. 73, no. 18, pp. 184408, May 2006. [22] Z. Li and S. Zhang, “Domain-wall dynamics driven by adiabatic spin-transfer torques,” Phys. Rev. B, vol. 70, no. 2, pp. 024417, Jul 2004. [23] A. Yamaguchi, T. Ono, S. Nasu, K. Miyake, K. Mibu, and T. Shinjo, “Real-space observation of current-driven domain wall motion in submicron magnetic wires,” Phys. Rev. Lett., vol. 92, no. 7, pp. 077205, Feb 2004. [24] M. Kl‥aui, P.-O. Jubert, R. Allenspach, A. Bischof, J. A. C. Bland, G. Faini, U. R‥udiger, C. A. F. Vaz, L. Vila, and C. Vouille, “Direct observation of domainwall configurations transformed by spin currents,” Phys. Rev. Lett., vol. 95, no. 2, pp. 026601, Jul 2005. [25] Masamitsu Hayashi, Luc Thomas, Charles Rettner, Rai Moriya, Yaroslaw B. Bazaliy, and Stuart S. P. Parkin, “Current driven domain wall velocities exceeding the spin angular momentum transfer rate in permalloy nanowires,” Phys. Rev. Lett., vol. 98, no. 3, pp. 037204, Jan 2007. [26] A. Vanhaverbeke, A. Bischof, and R. Allenspach, “Control of domain wall polarity by current pulses,” Phys. Rev. Lett., vol. 101, no. 10, pp. 107202, Sep 2008. [27] M. Hayashi, L. Thomas, Ya. B. Bazaliy, C. Rettner, R. Moriya, X. Jiang, and S. S. P. Parkin, “Influence of current on field-driven domain wall motion in permalloy nanowires from time resolved measurements of anisotropic magnetoresistance,” Phys. Rev. Lett., vol. 96, no. 19, pp. 197207, May 2006. 40 [28] Guido Meier, Markus Bolte, Ren’e Eiselt, Benjamin Kr‥uger, Dong-Hyun Kim, and Peter Fischer, “Direct imaging of stochastic domain-wall motion driven by nanosecond current pulses,” Phys. Rev. Lett., vol. 98, no. 18, pp. 187202, May 2007. [29] M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen Van Dau, F. Petroff, P. Etienne, G. Creuzet, A. Friederich, and J. Chazelas, “Giant magnetoresistance of (001)fe/(001)cr magnetic superlattices,” Phys. Rev. Lett., vol. 61, no. 21, pp. 2472– 2475, Nov 1988. [30] S. S. P. Parkin, R. Bhadra, and K. P. Roche, “Oscillatory magnetic exchange coupling through thin copper layers,” Phys. Rev. Lett., vol. 66, no. 16, pp. 2152–2155, Apr 1991. [31] A. E. Berkowitz, J. R. Mitchell, M. J. Carey, A. P. Young, S. Zhang, F. E. Spada, F. T. Parker, A. Hutten, and G. Thomas, “Giant magnetoresistance in heterogeneous cu-co alloys,” Phys. Rev. Lett., vol. 68, no. 25, pp. 3745–3748, Jun 1992. [32] M. Julliere, “Tunneling between ferromagnetic films,” Physics Letters A, vol. 54, no. 3, pp. 225 – 226, 1975. [33] Yoshinobu Nakatani, Andr Thiaville, and Jacques Miltat, “Head-to-head domain walls in soft nano-strips: a refined phase diagram,” Journal of Magnetism and Magnetic Materials, vol. 290-291, no. Part 1, pp. 750 – 753, 2005, Proceedings of the Joint European Magnetic Symposia (JEMS’ 04). [34] R.D. McMichael and M.J. Donahue, “Head to head domain wall structures in thin magnetic strips,” Magnetics, IEEE Transactions on, vol. 33, no. 5, pp. 4167 –4169, sep 1997. 41 [35] “Nmag - a micromagnetic simulation environment,” http://nmag.soten.ac. uk/, June 2007. 42 | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/37728 | - |
| dc.description.abstract | 本文主要是以數值模擬的方法研究缺陷對於準一維磁區動力學之影響。在此
研究中，我們設計了一個帶有四個缺陷之鐵磁奈米條紋，其系統磁化含有兩個磁 區，在兩磁區之間含有一頭對頭的磁區壁，且其磁化在系統兩端為固定，接著注 入沿平面流動之自旋偏極化電流，藉以驅動磁區壁移動；由於缺陷之影響，此系 統之磁化形成了兩個穩定態，應用不同電流密度之自旋偏極化電流，可驅使磁化 在兩穩定態之間轉換。我們發現，在電流關閉時，磁區壁會有反彈的效應，而此 效應只有在電流密度大於jcriticle且電流下降時間小於2 109秒時出現。 由於應用此效應，可以使用同方向之直流電控制磁區壁之位置，進而使元件更加簡化，因此反彈效應在自旋扭矩傳輸相關之元件設計有許多應用潛力。 | zh_TW |
| dc.description.abstract | We study the effect of defects on the dynamics of quasi-one-dimensional magnetic domain by simulation. In the present study, the system is composed of a ferromagnetic
nanostripe and four symmetric defects.The magnetization of the nanostripe is assumed to be pinned at the two end, and it contains a single domain wall.We use the spin polarized current flowed in the plane driving the domain wall motion.There are two stable states of magnetization due to defects.The different current density values and directions let the magnetization be transformed between the two stable states.We find that the domain wall was rebounded when the current was switched off.And the rebounding phenomenon appears only if the current density j is greater than j_criticle and the fall time is less than 2x10^9 second. The phenomenon could be used in STT-based devices because the domain wall location could be controlled by the direct current and the devices could be simpler. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-13T15:40:42Z (GMT). No. of bitstreams: 1 ntu-100-R97245015-1.pdf: 5447048 bytes, checksum: 19b53a533c33e3924ca53eee468eeb5a (MD5) Previous issue date: 2011 | en |
| dc.description.tableofcontents | 1 Introduction . . . . . . . . . . . . . . . . . . . . . 1
2 Method and Magnetism Background . . . . . . . . . . . . 3 2.1 The system cofiguration . . . . . . . . . . . . . . 3 2.2 Magnetoresistance . . . . . . . . . . . . . . . . . .3 2.2.1 Measurement methods of magnetoresistance . . . . 4 2.2.2 Introduction to several types of magnetoresistance .5 2.3 Domain wall structure in nanostripes . . . . . . . ..8 2.4 Landau-Lifshitz-Gilbert (LLG) equation and Spin Torque Transfer . . . . 10 2.5 Introduction to Nmag . . . . . . . . . . . . . . . . 11 2.6 Material Parameters . . . . . . . . . . . . . . . . 12 3 Results of the simulation . . . . . . . . . . . . . . . 14 3.1 Domain wall motion with different current density .. 14 3.1.1 j j j < j jc1 j . . . . . . . . . . . . . . . . ..14 3.1.2 j jc1 j j j j<j jc2 j . . . . . . . . . . . . . 16 3.1.3 j jc2 j j j j<j jc3 j . . . . . . . . . . . . . 18 3.1.4 j j j j jc3 j . . . . . . . . . . . . . . . . . .18 3.2 To control the magnetic bit by DC . . . . . . . . . 23 3.3 The relationship between rise time and critical current density . . . . . . 26 3.4 The relationship between fall time and critical density . . . . . . . . . . . 31 4 Conclusion . . . . . . . . . . . . . . . . . . . . . . 35 Reference . . . . . . . . . . . . . . . . . . . . . . . . 37 | |
| dc.language.iso | en | |
| dc.subject | 自旋扭矩傳輸 | zh_TW |
| dc.subject | 磁區壁 | zh_TW |
| dc.subject | 缺陷 | zh_TW |
| dc.subject | spin torque transfer | en |
| dc.subject | domain wall | en |
| dc.subject | defect | en |
| dc.title | 有缺陷之準一維系統磁區動力學 | zh_TW |
| dc.title | Dynamics of Quasi-One-Dimensional Magnetic Domain with Defects | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 99-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 許仁華(Jen-Hwa Hsu),楊志信(Jyh-Shinn Yang),衛榮漢(Zung-Hang Wei) | |
| dc.subject.keyword | 自旋扭矩傳輸,磁區壁,缺陷, | zh_TW |
| dc.subject.keyword | spin torque transfer,domain wall,defect, | en |
| dc.relation.page | 42 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2011-08-10 | |
| dc.contributor.author-college | 理學院 | zh_TW |
| dc.contributor.author-dept | 應用物理所 | zh_TW |
| 顯示於系所單位： | 應用物理研究所 | |
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