Co基稀土系记录薄膜磁化过程的微磁学模拟研究
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摘要
光磁混合记录方法,是一种可以突破超顺磁极限的限制,并进一步提高硬盘记录密度和读写速率的一种新型超高密度信息存储方式。它汲取了磁光记录以及磁记录的优点,信号写入采用的是激光辅助加热方式,信号读出则是采用高灵敏度的巨磁阻磁头检测磁通方式来进行。开展光磁混合记录介质的研究,对于提高硬盘的记录密度和实现光磁混合记录技术的实用化都有着极其重要的意义。本文围绕新型光磁混合记录介质SmDyCo、SmTbCo系薄膜的微观结构、物理特性及其相关机理,在实验和理论方面进行了比较深入和系统的研究。
运用微磁模型及微磁模拟软件SimulMag,对SmDyCo单层磁性膜、有软磁层的SmDyCo磁性膜的磁化特性,动态磁化过程以及读出特性进行了模拟研究,模拟结果与实验结果相吻合。运用微磁理论模型及微磁模拟软件SimulMag研究了双层耦合膜在外场作用下的磁化特性和读出特性,对双层耦合磁性薄膜加入软磁层后的磁化特性和读出特性进行了模拟研究。
运用微磁模型及微磁模拟软件OOMMF,对SmTbCo单层磁性膜在不同角度外磁场作用下的磁化特性、磁化过程状态以及能量密度变化进行了系统的模拟。运用微磁模型及微磁模拟软件OOMMF,研究了双层耦合膜的磁化特性和界面磁畴形成条件,运用相关理论解释了双层耦合膜的磁化特性。最后,对不同记录层厚度和读出层厚度情况下薄膜的交换能密度变化进行了研究。
Hybrid recording is a novel kind of super-high density information storage method that can break through the super-paramagnetic limit and further increase the recording density as well as the writing and reading data rates of hard disk drives (HDD). It takes advantages from MO and magnetic recording methods. The message writing is by laser-assisted thermal magnetic recording and message reading is by magnetic flux detection with high sensitive GMR sensors. The studies on the developing of new hybrid recording media are very important to the increasing of the area density of HDD and to the implementation of hybrid recoding method. Therefore, this dissertation presents a theoretical and experimental investigation of micro-structure and physical properties as well as relative mechanism of SmDyCo, SmTbCo series thin films for hybrid recording.
By using micro-magnetic model and micro-magnetic simulated software-SimulMag, we simulated the magnetic properties and dynamic magnetic process of SmDyCo single magnetic films and SmDyCo magnetic films with soft underlayer systemically. The simulation results were in good accord with the experimental results. The switching behaviors of exchange coupled layers under magnetic fields have been explained by using micro-magnetic model. Finally, we simulated the magnetic properties and readout properties of the exchange coupled double layers with a soft underlayer.
By using micro-magnetic model and micro-magnetic simulated software-OOMMF, we simulated the hysteresis properties and magnetization process of SmTbCo single magnetic films systemically at different angles. By using micro-magnetic model, we studied hysteresis properties and the forming condition of the interface magnetic domains of SmTbCo exchange coupled layers. We explained the magnetization of SmTbCo exchange coupled layers. Finally, we studied the effect of film thickness for exchange energy density.
运用微磁模型及微磁模拟软件SimulMag,对SmDyCo单层磁性膜、有软磁层的SmDyCo磁性膜的磁化特性,动态磁化过程以及读出特性进行了模拟研究,模拟结果与实验结果相吻合。运用微磁理论模型及微磁模拟软件SimulMag研究了双层耦合膜在外场作用下的磁化特性和读出特性,对双层耦合磁性薄膜加入软磁层后的磁化特性和读出特性进行了模拟研究。
运用微磁模型及微磁模拟软件OOMMF,对SmTbCo单层磁性膜在不同角度外磁场作用下的磁化特性、磁化过程状态以及能量密度变化进行了系统的模拟。运用微磁模型及微磁模拟软件OOMMF,研究了双层耦合膜的磁化特性和界面磁畴形成条件,运用相关理论解释了双层耦合膜的磁化特性。最后,对不同记录层厚度和读出层厚度情况下薄膜的交换能密度变化进行了研究。
Hybrid recording is a novel kind of super-high density information storage method that can break through the super-paramagnetic limit and further increase the recording density as well as the writing and reading data rates of hard disk drives (HDD). It takes advantages from MO and magnetic recording methods. The message writing is by laser-assisted thermal magnetic recording and message reading is by magnetic flux detection with high sensitive GMR sensors. The studies on the developing of new hybrid recording media are very important to the increasing of the area density of HDD and to the implementation of hybrid recoding method. Therefore, this dissertation presents a theoretical and experimental investigation of micro-structure and physical properties as well as relative mechanism of SmDyCo, SmTbCo series thin films for hybrid recording.
By using micro-magnetic model and micro-magnetic simulated software-SimulMag, we simulated the magnetic properties and dynamic magnetic process of SmDyCo single magnetic films and SmDyCo magnetic films with soft underlayer systemically. The simulation results were in good accord with the experimental results. The switching behaviors of exchange coupled layers under magnetic fields have been explained by using micro-magnetic model. Finally, we simulated the magnetic properties and readout properties of the exchange coupled double layers with a soft underlayer.
By using micro-magnetic model and micro-magnetic simulated software-OOMMF, we simulated the hysteresis properties and magnetization process of SmTbCo single magnetic films systemically at different angles. By using micro-magnetic model, we studied hysteresis properties and the forming condition of the interface magnetic domains of SmTbCo exchange coupled layers. We explained the magnetization of SmTbCo exchange coupled layers. Finally, we studied the effect of film thickness for exchange energy density.
引文
[1]王辉,黄致新,张峰,刘敏.硬盘磁记录介质的发展与展望.信息记录材料, 2006, 7(3): 28-31
[2] Moser A. Magnetic recording: advancing into the future. J. Phys. D: Appl. Phys., 2002, 35: R157-R167
[3]黄致新,许小红,晋芳,程晓敏,杨晓非,李佐宜.硬盘用高密度垂直磁记录薄膜研究进展.信息记录材料, 2002, 3(2): 47-52
[4] Richer H. J. Longitudinal recording at 10 to 20 Gb/in2 and beyond. IEEE. Trans. Magn. Sept. 1999, 35(5): 2790
[5] O’Grady K., Laidler H. The limits to magnetic recording---media consideration. J. Magn. Magn. Mater., 1999, 200: 616-633
[6] Wood R., Sonobe Y., Jin Z., et al. Perpendicular recording the promise and the problems. Journal of Magnetism and Magnetic Materials, 2001, 235: 1-9
[7] Iwasaki Shun-ichi. Perpendicular magnetic recording. IEEE Trans Magn. , 1980, 16(1): 71-76
[8] Kadakura S, Naoe M. Deposition of perpendicular magnetic recording Co-Cr layers with nanosize domain using a plasma enhanced type of sputtering apparatus. J Appl Phys, 1999, 85(8): 6127-6129
[9] Kadakura S, Naoe M, Nakagawa S, Maeda Y. Nanosize magnetic crystallite formation in Co-Cr thin films for perpendicular recording media. IEEE Trans Magn, 1998, 34(4): 1642-1647
[10] Futamoto M, Inaba N, Hirayama Y, Ito K, Honda Y. Microstructure and micromagnetics of future thin-film media. Journal of Magnetism and Magnetic Materials (Invited paper), 1999, 193: 36-43
[11] Lee Z Y, Chang L J and Sakurai Y. Galvanomagnetic Effects in Sm-Co Amorphous Magnetic Films. IEEE Trans J Magn Jpn, 1987, TJMJ-2(5): 467
[12] Numata T, Kiriyama H. Magnetic Anisotropy in SmCo Amorphous Films. J Appl Phys, 1998, 64(10): 5501-5503
[13] Seiya Ogawa. Magnetic materials and structures for thin-film recording media.Lecture at华中科技大学, Oct, 2001
[14]李佐宜.光磁混合存储是当前超高密度存储技术的研究方向.国际学术动态, 2005(6): 27-28
[15]韦玮,傅便翔,何杰,秦玉文.超高密度、高速光磁混合数字信息存储技术和存在的问题.中国科学基金, 2004(6): 339-341
[16] Hiroyuki Katayama, Kosuke Watanabe. Effect of underlayers of laser-assisted magnetic recording media on high-density recording. Appl. Phys. Lett., 2002, 81(26): 4994-4996
[17] S. Miyanishi, K. Kojima, J. Sato, K. Takayama, H. Fuji, A. Takahashi. High -density laser-assisted magnetic recording on TbFeCo media with an Al underlayer. J Appl Phys, 2003, 93(10): 7801-7803
[18] M. Tofizur Rahman, Xiaoxi Liu, Akimitsu Morisako. TiN underlayer and overlayer for TbFeCo perpendicular magnetic recording media. Journal of Magnetism and Magnetic Materials 303 (2006): e133–e136
[19] Shiro Mifuji, Hiroshi Sakuma, and Kiyoshi Ishii. Co–Pt/Pt thin films with perpendicular magnetization and a high coercivity prepared by gas flow sputtering. J Appl Phys 97, 10N102 (2005)
[20]薛双喜,王浩,杨辅军,王君安,曹歆. Ag对CoPt/Ag纳米复合膜的结构与磁性的影响.物理学报, 2005(11): 92-94
[21]展晓元,张跃,顾有松,郑小兰,张大勇. Ag衬底层对FePt薄膜结构和性能的影响.功能材料, 2006(2): 203-206
[22] W.F. Brown. Micromagnetic. Intersci Pub, New York, 1963
[23] Landau I., Lifshitz E. Electrodynamique des milieux continues. Mir Moscou, 1969
[24] Frei E.H., Shtrikman S., and Treves D. Critical size and nucleation field of ideal ferromagnetic particles. Phys, Rev, 1957, 106: 446
[25] Aharoni A., Shtrikman S. Magnetization curve of the infinite cylinder. Phys, Rev, 1958, 109: 1522
[26]蒲富恪,李伯臧.微磁学初步.北京:中国科学院物理所, 1983
[27] Brown Jr. W.F. Theory of the approach to magnetic saturation. Phys, Rev, 1940, 58: 736
[28] Brown Jr. W.F. Criterion for uniform micromagnetization. Phys, Rev, 1957, 105: 1479
[29]钟智勇,陈伟元,王豪才.磁性薄膜的微磁学计算机模拟与显微成像技术.磁性材料及器件, 1996, 27(4): 36-37
[30] Josef Fidler and Thomas Schrefl. Micromagnetic modelling—the current state of the art. J. Appl. Phys. 33(2000): R135–R156
[31] http://www. math.nist.gov/oommf/contrib/simulmag/
[32] http://www.nist.gov/oommf/
[33] Lijie Guan. Micromagnetic study of advanced magnetic thin film media for ultra-high density recording. Ph. D. thesis, Carnegie Mellon University, Pennsylvania, 2002
[34]李景涌.有限元法.北京:北京邮电大学出版社, 1999
[35]王勖成,邵敏.有限单元法基本原理与数值方法.北京:清华大学出版社, 1988
[36]傅永华.有限元分析基础.武汉:武汉大学出版社, 2003
[37]王现英,张约品,沈德芳,干福熹.超高密度磁光存储及其介质研究进展.物理, 2001, 31(12): 779-783
[38] Wood R. The feasibility of magnetic recording at 1 tera bit per square inch. IEEE Trans. Magn., Sept. 1999, 35(5): 2790
[39] Qingzhi Peng. Microstructural dependence of magnetization process in thin film recording media. Ph. D. thesis, University of California, California, 1997
[40] Yee K S. Numerical solution of initial boundary value problems involving Maxwell equations in isotropic media. IEEE Trans. Antennas & Propagat., 1966, 14(3): 302-307
[41] Jonkers P. A. E. Magneto-resistance in magnetic domain wall systems. Journal of Magnetism and Magnetic Materials, 2002, 247: 178-186
[2] Moser A. Magnetic recording: advancing into the future. J. Phys. D: Appl. Phys., 2002, 35: R157-R167
[3]黄致新,许小红,晋芳,程晓敏,杨晓非,李佐宜.硬盘用高密度垂直磁记录薄膜研究进展.信息记录材料, 2002, 3(2): 47-52
[4] Richer H. J. Longitudinal recording at 10 to 20 Gb/in2 and beyond. IEEE. Trans. Magn. Sept. 1999, 35(5): 2790
[5] O’Grady K., Laidler H. The limits to magnetic recording---media consideration. J. Magn. Magn. Mater., 1999, 200: 616-633
[6] Wood R., Sonobe Y., Jin Z., et al. Perpendicular recording the promise and the problems. Journal of Magnetism and Magnetic Materials, 2001, 235: 1-9
[7] Iwasaki Shun-ichi. Perpendicular magnetic recording. IEEE Trans Magn. , 1980, 16(1): 71-76
[8] Kadakura S, Naoe M. Deposition of perpendicular magnetic recording Co-Cr layers with nanosize domain using a plasma enhanced type of sputtering apparatus. J Appl Phys, 1999, 85(8): 6127-6129
[9] Kadakura S, Naoe M, Nakagawa S, Maeda Y. Nanosize magnetic crystallite formation in Co-Cr thin films for perpendicular recording media. IEEE Trans Magn, 1998, 34(4): 1642-1647
[10] Futamoto M, Inaba N, Hirayama Y, Ito K, Honda Y. Microstructure and micromagnetics of future thin-film media. Journal of Magnetism and Magnetic Materials (Invited paper), 1999, 193: 36-43
[11] Lee Z Y, Chang L J and Sakurai Y. Galvanomagnetic Effects in Sm-Co Amorphous Magnetic Films. IEEE Trans J Magn Jpn, 1987, TJMJ-2(5): 467
[12] Numata T, Kiriyama H. Magnetic Anisotropy in SmCo Amorphous Films. J Appl Phys, 1998, 64(10): 5501-5503
[13] Seiya Ogawa. Magnetic materials and structures for thin-film recording media.Lecture at华中科技大学, Oct, 2001
[14]李佐宜.光磁混合存储是当前超高密度存储技术的研究方向.国际学术动态, 2005(6): 27-28
[15]韦玮,傅便翔,何杰,秦玉文.超高密度、高速光磁混合数字信息存储技术和存在的问题.中国科学基金, 2004(6): 339-341
[16] Hiroyuki Katayama, Kosuke Watanabe. Effect of underlayers of laser-assisted magnetic recording media on high-density recording. Appl. Phys. Lett., 2002, 81(26): 4994-4996
[17] S. Miyanishi, K. Kojima, J. Sato, K. Takayama, H. Fuji, A. Takahashi. High -density laser-assisted magnetic recording on TbFeCo media with an Al underlayer. J Appl Phys, 2003, 93(10): 7801-7803
[18] M. Tofizur Rahman, Xiaoxi Liu, Akimitsu Morisako. TiN underlayer and overlayer for TbFeCo perpendicular magnetic recording media. Journal of Magnetism and Magnetic Materials 303 (2006): e133–e136
[19] Shiro Mifuji, Hiroshi Sakuma, and Kiyoshi Ishii. Co–Pt/Pt thin films with perpendicular magnetization and a high coercivity prepared by gas flow sputtering. J Appl Phys 97, 10N102 (2005)
[20]薛双喜,王浩,杨辅军,王君安,曹歆. Ag对CoPt/Ag纳米复合膜的结构与磁性的影响.物理学报, 2005(11): 92-94
[21]展晓元,张跃,顾有松,郑小兰,张大勇. Ag衬底层对FePt薄膜结构和性能的影响.功能材料, 2006(2): 203-206
[22] W.F. Brown. Micromagnetic. Intersci Pub, New York, 1963
[23] Landau I., Lifshitz E. Electrodynamique des milieux continues. Mir Moscou, 1969
[24] Frei E.H., Shtrikman S., and Treves D. Critical size and nucleation field of ideal ferromagnetic particles. Phys, Rev, 1957, 106: 446
[25] Aharoni A., Shtrikman S. Magnetization curve of the infinite cylinder. Phys, Rev, 1958, 109: 1522
[26]蒲富恪,李伯臧.微磁学初步.北京:中国科学院物理所, 1983
[27] Brown Jr. W.F. Theory of the approach to magnetic saturation. Phys, Rev, 1940, 58: 736
[28] Brown Jr. W.F. Criterion for uniform micromagnetization. Phys, Rev, 1957, 105: 1479
[29]钟智勇,陈伟元,王豪才.磁性薄膜的微磁学计算机模拟与显微成像技术.磁性材料及器件, 1996, 27(4): 36-37
[30] Josef Fidler and Thomas Schrefl. Micromagnetic modelling—the current state of the art. J. Appl. Phys. 33(2000): R135–R156
[31] http://www. math.nist.gov/oommf/contrib/simulmag/
[32] http://www.nist.gov/oommf/
[33] Lijie Guan. Micromagnetic study of advanced magnetic thin film media for ultra-high density recording. Ph. D. thesis, Carnegie Mellon University, Pennsylvania, 2002
[34]李景涌.有限元法.北京:北京邮电大学出版社, 1999
[35]王勖成,邵敏.有限单元法基本原理与数值方法.北京:清华大学出版社, 1988
[36]傅永华.有限元分析基础.武汉:武汉大学出版社, 2003
[37]王现英,张约品,沈德芳,干福熹.超高密度磁光存储及其介质研究进展.物理, 2001, 31(12): 779-783
[38] Wood R. The feasibility of magnetic recording at 1 tera bit per square inch. IEEE Trans. Magn., Sept. 1999, 35(5): 2790
[39] Qingzhi Peng. Microstructural dependence of magnetization process in thin film recording media. Ph. D. thesis, University of California, California, 1997
[40] Yee K S. Numerical solution of initial boundary value problems involving Maxwell equations in isotropic media. IEEE Trans. Antennas & Propagat., 1966, 14(3): 302-307
[41] Jonkers P. A. E. Magneto-resistance in magnetic domain wall systems. Journal of Magnetism and Magnetic Materials, 2002, 247: 178-186