L1_0FePt梯度各向异性介质研究
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摘要
硬盘磁记录已经有半个多世纪的发展历史,其中薄膜感应磁头、磁阻磁头、巨磁阻多层膜等几项技术的革新使得磁记录技术得到迅猛发展,磁记录面密度也快速增长。但是,在经历了上个世纪九十年代的黄金发展期之后,目前的磁记录技术已经受到了超顺磁极限的限制。为了保证信息能够长期存储,要求存储介质具有一定的热稳定性,这就对晶粒体积及各向异性大小有一定要求,二者乘积要大于45KbT；为了进一步增加面密度我们必须减小每一个记录单元的尺寸,而信噪比与记录单元中晶粒数目有关,因此在保证足够信噪比的情况下我们只能通过减小晶粒的尺寸来增加面密度；同时热稳定性又要求我们在减小晶粒体积的同时必须选用高各向异性材料,而各向异性太高又会导致信息写入比较困难(有可能超出写入场能力范围),因为翻转场与记录介质的各向异性常数呈正比。这样,热稳定性、写入场和信噪比三个因素相互制约形成了限制超高密度磁记录发展的三难困境。
为了克服超顺磁极限进一步提高磁记录面密度,许多新兴的磁记录技术被提出并投入研究,例如现在已经替代纵向磁记录的垂直磁记录,还有热辅助磁记录、微波辅助磁记录、图案化磁记录、以及叠加磁记录(Shingle Write)。另外,在记录介质改进方面,Suess等人提出了梯度各向异性介质原理,利用畴壁位移方式代替一致转动,也有望在现有工艺基础上来克服磁记录技术的三难困境,实现更高的磁记录密度。
为了在实验中验证梯度各向异性介质这一原理并证明其优异性,许多课题组对此展开了研究。他们在薄膜生长过程中通过改变成分、厚度、或者温度,证明了在实验中生长梯度各向异性介质的可行性。但是在磁性薄膜中较难验证梯度各向异性介质原理,因为很难保证畴壁是沿垂直膜面方向在一个记录单元内运动,有可能畴壁在面内横向运动,而梯度各向异性介质原理则是以单一记录单元为基础并且畴壁沿垂直方向移动,因此不能进行比较。为了从根本上验证梯度各向异性介质的优异性,我们以高各向异性FePt材料为基础,通过改变衬底温度生长了各向异性线性梯度发布的L10FePt薄膜,利用电子束曝光及离子束刻蚀等手段制备了其纳米柱阵列,并对其微结构及磁性进行了仔细研究。
本论文的工作主要分三部分,见正文第3、4、5章。第一部分的工作主要为10nmFePt均一各向异性薄膜的制备以及结构和磁性的表征。我们利用外接热耦的方式对样品拖表面的实际温度进行了校温,获得了加热炉丝与样品拖温度之间的关系曲线；然后我们使用磁控溅射仪在不同温度下生长了一系列10nmFePt薄膜。薄膜以MgO(001)为衬底,XRD数据表明薄膜取向为(001)方向,超晶格(001)峰随着温度的升高而增强,通过对(001)峰和(002)峰的积分我们得到了有序化参数和生长温度之间的关系。磁性表征结果表明样品的磁性随着温度的升高而增强,通过计算我们得出了磁晶各向异性常数与温度之间的关系。这为下一步精确生长线性各向异性FePt薄膜提供了必要的条件。
第二部分工作主要是线性及均一各向异性FePt薄膜及纳米柱的制备和性质表征。我们在第一部分工作的基础上生长了45nm线性及均一各向异性FePt薄膜,并用离子束曝光和离子减薄仪将薄膜刻蚀成了直径为80nm左右,周期为100nm的纳米柱。我们对纳米柱的磁性进行了表征,磁滞回线表明相较于均一各向异性FePt纳米柱,线性各向异性FePt纳米柱的矫顽场要明显减小；直流退磁(DCD)矫顽场的测量结果表明均一各向异性FePt纳米柱的剩磁矫顽场比线性纳米柱的要高,两者的热稳定性因子均超过100,即表示两种纳米柱的磁性可以保存很长的时间；拟合计算表明线性各向异性FePt纳米柱的优值因子ξ=2△E/(MSHSWV)要比均一各向异性纳米柱的大61%,充分显示了梯度各向异性介质的优异性;从翻转场分布曲线可以看出线性各向异性FePt纳米柱的成核场要小于均一各向异性纳米柱的成核场,同时线性纳米柱的翻转场分布峰宽较窄,表明样品中软磁和硬磁相之间有很强的耦合作用。
第三部分工作主要是对线性及均一各向异性FePt薄膜的微结构进行了表征。我们采用聚焦离子束(FIB)、三角抛光器(Tripod Polisher)和精密离子减薄仪(PIPS)制成了较高质量的截面TEM样品。从高分辨结果可以看出薄膜与衬底界面较清晰,为准外延状态。我们沿着生长方向对线性各向异性FePt薄膜不同区域的傅立叶变换中001和002衍射点强度与位置分布进行了计算,结果表明样品中的各向异性分布与生长样品时设计的各向异性分布基本一致。
It has been more than a half century since magnetic recording was applied to computer's data storage, some new technologies like thin-film inducted heads, magnetoresistive heads, the giant magnetic resistance multilayer membrane had pushed the rapid development of the magnetic recording, so the magnetic recording areal density grew rapidly. After through a "golden time" in1990s, the longitudinal magnetic recording has met its superparamagnetic limitation in the early period of the21st century. The product of the volume of the crystalline grain and the magnetocrystalline anisotropy must be greater than45to insure the thermal stability of the storage media; in order to increase the areal density we have to reduce the size of the crystalline grain while keeping the signal to noise ratio; however, to maintain the thermal stability, we have to choose the materials with high magnetocrystalline anisotropy if we reduce the size of the crystalline grain, but high magnetocrystalline anisotropy will result in the difficulty of the writing of the information (may exceed the writablity). So the thermal stability, writability and signal to noise ratio form the so-called recording trilemma.
To overcome the superparamagnetic limitation and further increase the areal density of the magnetic recording, some new technologies have been proposed and put into study, like perpendicular magnetic recording, which has already replaced the longitudinal magnetic recording, and heat-assisted magnetic recording, microwave-assisted magnetic recording, patterned magnetic recording media, shingled write recording and so on. Suess etc. has proposed the concept of anisotropy graded media, in which the domain wall motion replaces the coherent rotation. Anisotropy graded media is promising to overcome recording trilemma in achieving ultrahigh areal density.
In order to prove the concept of anisotropy graded media and its advantage experimentally, some experiments have been conducted in this area. However, most experimental works on anisotropy graded media are focused on the continuous films, where the magnetization reversal is dominated by domain nucleation and subsequent lateral propagation. It is not suitable to compare the results of graded films with the theoretical model, which is based on isolated grains with graded anisotropy and the domain wall propagates from soft to hard ends vertically. In order to further prove the concept of "graded" anisotropy media, it is highly desirable to experimentally study patterned media with graded anisotropy based on L10-FePt films.
First, we grew10nm FePt uniform anisotropy films and characterized their structure and magnetic properties. We got the real temperature of the sample holder and its relationship with the heating Ta wire by mounting a thermal couple on it; then a series of10nm FePt films with uniform anisotropy were grown on MgO(001) at temperatures ranging from290℃to650℃; The XRD data shows that the growing direction of the film is (001) and the intensity of the superlattice (001) peak increases as the temperature arises, after calculation we got the relationship of the ordering parameter and the growing temperature by the integration of the (001) and (002) peak. The MH curves data indicates that the films are anisotropic and the anisotropy increases as the raise of the growing temperature, the relationship between the anisotropy and the growing temperature was got.
Second, based on the former work, we grew45nm linear and uniform anisotropy distribution FePt films and characterized their properties. The films are etched into nanopillar arrays using Electron Lithography Exposure and Ion Milling, which diameter is around80nm, and the inner distance among pillars is100nm. The coercivity of the nanopillar arrays with graded anisotropy is smaller than that of the uniform ones; the magnetic properties of patterned nanopillar arryas with both uniform anisotropy and linearly graded anisotropy are further characterized by the temperature-dependent coercivity measurement, the patterned Fept nanopillar arrays with uniform anisotropy exhibit a larger Ho compared to nanopillar arrays with linearly graded anisotropy; the calculated thermal stability factors KUV/kBT, for both samples are beyond100, indicating that the magnetization could be stable for more than a decade. Furthermore, the calculated relative figure of merit (ζ=2△E/(MSHSWV)for FePt nanopillar arrays with linearly graded anisotropy is61%larger tha that of the FePt nanopillar arrays with uniform anisotropy, which indicates the advantage of the anisotropy graded media; the switching field distribution of FePt nanopillars with linearly graded anisotropy exhibits a relatively narrow peak, which indicates that the soft and hard phases in the sample are strongly coupled.
Last, we characterized the microstructure of the linear and uniform anisotropy distribution FePt films. We used FIB, tripod polisher and PIPS make high quality TEM samples. The HRTEM data shows that the interface of the film and the substrate is clear, the film is quasi-epitaxial growth. We calculated the intensity and position of the001and002diffraction spots in the FFT of different areas along the growth direction of the linear sample, which indicates the linear distribution of the anisotropy as expected.
为了克服超顺磁极限进一步提高磁记录面密度,许多新兴的磁记录技术被提出并投入研究,例如现在已经替代纵向磁记录的垂直磁记录,还有热辅助磁记录、微波辅助磁记录、图案化磁记录、以及叠加磁记录(Shingle Write)。另外,在记录介质改进方面,Suess等人提出了梯度各向异性介质原理,利用畴壁位移方式代替一致转动,也有望在现有工艺基础上来克服磁记录技术的三难困境,实现更高的磁记录密度。
为了在实验中验证梯度各向异性介质这一原理并证明其优异性,许多课题组对此展开了研究。他们在薄膜生长过程中通过改变成分、厚度、或者温度,证明了在实验中生长梯度各向异性介质的可行性。但是在磁性薄膜中较难验证梯度各向异性介质原理,因为很难保证畴壁是沿垂直膜面方向在一个记录单元内运动,有可能畴壁在面内横向运动,而梯度各向异性介质原理则是以单一记录单元为基础并且畴壁沿垂直方向移动,因此不能进行比较。为了从根本上验证梯度各向异性介质的优异性,我们以高各向异性FePt材料为基础,通过改变衬底温度生长了各向异性线性梯度发布的L10FePt薄膜,利用电子束曝光及离子束刻蚀等手段制备了其纳米柱阵列,并对其微结构及磁性进行了仔细研究。
本论文的工作主要分三部分,见正文第3、4、5章。第一部分的工作主要为10nmFePt均一各向异性薄膜的制备以及结构和磁性的表征。我们利用外接热耦的方式对样品拖表面的实际温度进行了校温,获得了加热炉丝与样品拖温度之间的关系曲线；然后我们使用磁控溅射仪在不同温度下生长了一系列10nmFePt薄膜。薄膜以MgO(001)为衬底,XRD数据表明薄膜取向为(001)方向,超晶格(001)峰随着温度的升高而增强,通过对(001)峰和(002)峰的积分我们得到了有序化参数和生长温度之间的关系。磁性表征结果表明样品的磁性随着温度的升高而增强,通过计算我们得出了磁晶各向异性常数与温度之间的关系。这为下一步精确生长线性各向异性FePt薄膜提供了必要的条件。
第二部分工作主要是线性及均一各向异性FePt薄膜及纳米柱的制备和性质表征。我们在第一部分工作的基础上生长了45nm线性及均一各向异性FePt薄膜,并用离子束曝光和离子减薄仪将薄膜刻蚀成了直径为80nm左右,周期为100nm的纳米柱。我们对纳米柱的磁性进行了表征,磁滞回线表明相较于均一各向异性FePt纳米柱,线性各向异性FePt纳米柱的矫顽场要明显减小；直流退磁(DCD)矫顽场的测量结果表明均一各向异性FePt纳米柱的剩磁矫顽场比线性纳米柱的要高,两者的热稳定性因子均超过100,即表示两种纳米柱的磁性可以保存很长的时间；拟合计算表明线性各向异性FePt纳米柱的优值因子ξ=2△E/(MSHSWV)要比均一各向异性纳米柱的大61%,充分显示了梯度各向异性介质的优异性;从翻转场分布曲线可以看出线性各向异性FePt纳米柱的成核场要小于均一各向异性纳米柱的成核场,同时线性纳米柱的翻转场分布峰宽较窄,表明样品中软磁和硬磁相之间有很强的耦合作用。
第三部分工作主要是对线性及均一各向异性FePt薄膜的微结构进行了表征。我们采用聚焦离子束(FIB)、三角抛光器(Tripod Polisher)和精密离子减薄仪(PIPS)制成了较高质量的截面TEM样品。从高分辨结果可以看出薄膜与衬底界面较清晰,为准外延状态。我们沿着生长方向对线性各向异性FePt薄膜不同区域的傅立叶变换中001和002衍射点强度与位置分布进行了计算,结果表明样品中的各向异性分布与生长样品时设计的各向异性分布基本一致。
It has been more than a half century since magnetic recording was applied to computer's data storage, some new technologies like thin-film inducted heads, magnetoresistive heads, the giant magnetic resistance multilayer membrane had pushed the rapid development of the magnetic recording, so the magnetic recording areal density grew rapidly. After through a "golden time" in1990s, the longitudinal magnetic recording has met its superparamagnetic limitation in the early period of the21st century. The product of the volume of the crystalline grain and the magnetocrystalline anisotropy must be greater than45to insure the thermal stability of the storage media; in order to increase the areal density we have to reduce the size of the crystalline grain while keeping the signal to noise ratio; however, to maintain the thermal stability, we have to choose the materials with high magnetocrystalline anisotropy if we reduce the size of the crystalline grain, but high magnetocrystalline anisotropy will result in the difficulty of the writing of the information (may exceed the writablity). So the thermal stability, writability and signal to noise ratio form the so-called recording trilemma.
To overcome the superparamagnetic limitation and further increase the areal density of the magnetic recording, some new technologies have been proposed and put into study, like perpendicular magnetic recording, which has already replaced the longitudinal magnetic recording, and heat-assisted magnetic recording, microwave-assisted magnetic recording, patterned magnetic recording media, shingled write recording and so on. Suess etc. has proposed the concept of anisotropy graded media, in which the domain wall motion replaces the coherent rotation. Anisotropy graded media is promising to overcome recording trilemma in achieving ultrahigh areal density.
In order to prove the concept of anisotropy graded media and its advantage experimentally, some experiments have been conducted in this area. However, most experimental works on anisotropy graded media are focused on the continuous films, where the magnetization reversal is dominated by domain nucleation and subsequent lateral propagation. It is not suitable to compare the results of graded films with the theoretical model, which is based on isolated grains with graded anisotropy and the domain wall propagates from soft to hard ends vertically. In order to further prove the concept of "graded" anisotropy media, it is highly desirable to experimentally study patterned media with graded anisotropy based on L10-FePt films.
First, we grew10nm FePt uniform anisotropy films and characterized their structure and magnetic properties. We got the real temperature of the sample holder and its relationship with the heating Ta wire by mounting a thermal couple on it; then a series of10nm FePt films with uniform anisotropy were grown on MgO(001) at temperatures ranging from290℃to650℃; The XRD data shows that the growing direction of the film is (001) and the intensity of the superlattice (001) peak increases as the temperature arises, after calculation we got the relationship of the ordering parameter and the growing temperature by the integration of the (001) and (002) peak. The MH curves data indicates that the films are anisotropic and the anisotropy increases as the raise of the growing temperature, the relationship between the anisotropy and the growing temperature was got.
Second, based on the former work, we grew45nm linear and uniform anisotropy distribution FePt films and characterized their properties. The films are etched into nanopillar arrays using Electron Lithography Exposure and Ion Milling, which diameter is around80nm, and the inner distance among pillars is100nm. The coercivity of the nanopillar arrays with graded anisotropy is smaller than that of the uniform ones; the magnetic properties of patterned nanopillar arryas with both uniform anisotropy and linearly graded anisotropy are further characterized by the temperature-dependent coercivity measurement, the patterned Fept nanopillar arrays with uniform anisotropy exhibit a larger Ho compared to nanopillar arrays with linearly graded anisotropy; the calculated thermal stability factors KUV/kBT, for both samples are beyond100, indicating that the magnetization could be stable for more than a decade. Furthermore, the calculated relative figure of merit (ζ=2△E/(MSHSWV)for FePt nanopillar arrays with linearly graded anisotropy is61%larger tha that of the FePt nanopillar arrays with uniform anisotropy, which indicates the advantage of the anisotropy graded media; the switching field distribution of FePt nanopillars with linearly graded anisotropy exhibits a relatively narrow peak, which indicates that the soft and hard phases in the sample are strongly coupled.
Last, we characterized the microstructure of the linear and uniform anisotropy distribution FePt films. We used FIB, tripod polisher and PIPS make high quality TEM samples. The HRTEM data shows that the interface of the film and the substrate is clear, the film is quasi-epitaxial growth. We calculated the intensity and position of the001and002diffraction spots in the FFT of different areas along the growth direction of the linear sample, which indicates the linear distribution of the anisotropy as expected.
引文
[1]E. D. Daniel, C. D. Mee, M. H. Clark, IEEE press, "Magnetic Recording the first 100 years"
[2]http://www-03.ibm.com/ibm/history/exhibits/storage/storage_fifty2.html
[3]J-Ulrich Thiele, Magnetic Recording, IEEE magnetic summer school, Nanjing.
[4]M. H. Kryder, and R. W. Gustafson, J. Magn. Magn. Mater,287,449 (2005).
[5]Iwasaki, S., Perpendicular magnetic recording[J]. IEEE Transactions on magnetic, (1980)
[6]Sakhrat Khizroev, Dmitri Litvnovi, "Perpendicular Magnetic Recording"
[7]B. Dipert, and L. Hebert, IEEE. Spectrum 30,48 (1993).
[8]P. Pavan, R. Bez, P. Olivo, and E. Zanoni, Proceedings of the IEEE,85,1248 (1997).
[9]R. Bez, E. Camerlenghi, A. Modelli, and A. Visconti, Proceedings of the IEEE, 91,489 (2003).
[10]G. Lawton, Computer,39,16 (2006).
[11]http://en.wikipedia.org/wiki/solid-state_drive
[12]http://embeddedstar.com/weblog/2009/01/25/bitmirco-ssd-idc
[13]http://www.networkworld.com/news/2009/041009-first-512gb-ssd-drive-offered. html.
[14]W. F. Brown, Phys. Rev.130,1677(1963).
[15]J. L. Dormann, D. Fiorani, and E. Tronc, Adv. Chem. Phys.98,283 (1997).
[16]S. Batra, J. D. Hannary, Z. Hong, and J. S. Goldberg, IEEE. Trans. Magn.40,319 (2004).
[17]R. M. Metzger, V. V. Konovalov, M. Sun, T. Xu, G. Zangari, B. Xu, M. Benakli, W. D. Doyle, IEEE Trans. Magn.36,30 (2000).
[18]H. J. Richter, and A. Y. Dobin, J. Magn. Magn. Mater.287,41 (2005).
[19]K. W. Ng, S. H. Leong, Z. Yuan, B. Liu, and Y. Ma, Appl. Phys. Lett.91,172511 (2007).
[20]http://www.mcplive.cn/index.php/article/index/id/11460
[21]R. L. White, R. M. H. Newt, and R. F. W. Pease, IEEE. Trans. Magn.33,990 (1997)
[22]J. Lohau, A. Moser, C. T. Rettner, M. E. Best, and B. D. Terris, Appl. Phys. Lett.79, 990(2001)
[23]J. Moritz, L. Buda, B. Dieny, J. P. Mozieres, R. Veerdonk, T. M. Crawford amd D. Weller, Appl. Phys. Lett.84,1519 (2004).
[24]B. D. Terris, T. Thomson, and F. Hu, Microsyst Technol.13,189 (2007).
[25]S. Y. Chou, P. R. Krauss, W. Zhang, L. Guo, and L. Zhuang, J. Vac. Sci. Technol. 15,2897(1997).
[26]Jianming Zhu and Yiming Wang, IEEE Trans. Magn.46,3 (2010)
[27]Terumitsu Tanaka, Shota Kashiwagi, Yoshitoki Furomoto, Yuto Otsuka and Kimihide Matsuyama, Nanoscale Research Letters 8,461 (2013)
[28]T. Tanaka, A. kato, Y. Furomoto, A. F. Md Nor, Y. Kanai and K. Matsuyama, J. Appl. Phys. 111,07B711 (2012)
[29]Tim Feldman and Garth Gibson,"Shingled Magnetic Recording- Areal Density Increase Requires New Data Management"
[30]http://www.seagate.com/au/en/tech-insights/breaking-areal-density-barriers-with-sea gate-smr-master-ti/ Victora, IEEE Trans Magn 41,537 (2005)
[31]Y. Y. Zou, J. P. Wang, C. H. Hee, and T. C. Chong, Appl. Phys. Lett.82,2473 (2003).
[32]H. J. Richter, IEEE. Trans. Magn.29,2258 (1993).
[33]R. Victora and X. Shen, IEEE Trans. Magn.41,537 (2005).
[34]D. Suess, T.Schrefl, S. Fahler, M. Krischner G. Hrkac, F. Dofbauer and J. Fiedler, Appl. Phys. Lett.87,012504 (2005).
[35]Z. Lu, P. B. Visscher and W. H. Butler, IEEE Trans. Magn.43,2941 (2007).
[36]B. J. Kirby, J. E. Davies, Kai Liu, S. M. Watson, G. T. Zimanyi, R. D. Shull, P. A. Kienzle, and J. A. Borchers, Phys. Rev. B 81,100405 (2010)
[37]Randy K. Dumas, Chaolin Zha, Yeyu Fang, Valentina Bonanni, June W. Lau, Josep Nogues, and Johan Akerman, IEEE Trans. Magn.47,6 (2011)
[38]J. E. Davies, P. Morrow, C. L. Dennis, J. W. Lau, B. Mcmorran, A. Cochran, J. Unguris, R. K. Dumas, P. Greene, and Kai Liu, J. Appl. Phys.109,07B909 (2011)
[39]Zhihong Lu, Junbo Guo, Zhanghua Gan, Yong Liu, Rui Xiong, G. J. Mankey, and W. H. Butler, J. Appl. Phys.113,073912 (2013)
[40]D. Weller et al. IEEE Trans. Magn.36,10 (2000)
[1]李学周,万英超,姜祥祺,杜元成,真空沉积技术,浙江大学出版社,1994.
[2]唐伟忠,薄膜材料制备原理、技术及应用,冶金工业出版社,1998.
[3]R. Y. Umetsu, C. Mitsumata, A. Sakuma, and K. Fukamichi, Trans. Magn. Soc. Jpn. 3,59 (2003).
[4]H. Zijlstra, Rev. Sci. Instrum.41,1241 (1970)
[5]R. Reeves, J. Phys. E 5,547 (1972)
[6]W. Roos, K.A. Hempel, C. Voight, H. Dedericks, R. Schippan, Rev. Sci. Instrum. 51,612(1980)
[7]H. J. Richter, K. A. Hempel, J. Pfeiffer, Rev. Sci. Instrum.59,1388 (1988)
[8]P. J. Flanders, J. Appl. Phys.63,3940 (1988)
[9]Th. Frey, W. Jantz, R. Stibal, J. Appl. Phys.64,6002 (1988)
[10]P. J. Flanders, Rev. Sci. Instrum.61,839 (1990)
[11]K. O'Grady, V. G. Lewis, D. P. E. Dickson, J. Appl. Phys.73,5608 (1993)
[1]S. Okamoto, N. Kikuchi, O. Kitakami, T. Miyazaki, Y. Shimada, and K. Fukamichi, Phys. Rev. B 66,024413 (2002)
[2]R. F. C. Farrow, D. Weller, R. F. Marks, M. F. Toney, S. Hom, G. R. Harp, and A. Cebollada, Appl. Phys. Lett.69,1166 (1996)
[3]Li-Lien Lee, B. K. Cheong,a) D. E. Laughlin, and D. N. Lambeth, Appl. Phys. Lett.67,24(1995)
[4]J. S. Chenand B. C. Lim, J. F. Hu, Y. K. Lim, and B. Liu, G. M. Chow, Appl. Phys. Lett.90,042508 (2007)
[5]P. Ho, G. C. Han,2 G. M. Chow,l and J. S. Chen,Appl. Phys. Lett.98,252503 (2011)
[6]T. Shimaa) and K. Takanashi,Y. K. Takahashi and K. Hono, Appl. Phys. Lett.85, 13 (2004)
[7]W.B. Mi, J. Jin, H.L. Bai,Journal of Alloys and Compounds 509 (2011)
[8]E. Yang and D. E. Laughlin, J. Appl. Phys.104 (2008)
[9]Z. L. Zhao, J. S. Chen, J. Ding, J. B. Yi, and B. H. Liu, J. P. Wang, Appl. Phys. Lett.88,052503 (2003)
[10]Y.K. Takahashia, K. Honoa, T. Shimab, K. Takanashi, Journal of Magnetism and Magnetic Materials 267 (2003)
[11]Y.F. Ding, J.S. Chena,_, E. Liub, L. Li, Journal of Magnetism and Magnetic Materials 303 (2006)
[12]Y. Zhang,a) J. Wan, V. Skumryev,b) S. Stoyanov, Y. Huang, and G. C. Hadjipanayis, D. Weller, Appl. Phys. Lett.85,22 (2004)
[13]B. D. Cullity, Elements of X-ray diffraction (Addison-Wesley Publishing Company, Inc., (1978)
[14]B. D. Cullity, Elements of X-ray diffraction (Addison-Wesley Publishing Company, Inc., (1978)
[15]O.A. Ivanov, L. V. Solina, V. A. Demshina, and L. M. Magat, Fiz. Met. Metalloved,35,92(1973)
[16]K. Coffey, M. A. Parker, and J. K. Howard, IEEE Trans. Magn.31,2737 (1995)
[17]V. V. Maykov, A. Ye. Yermakov, G. V. Ivanov, V. I. Khrabrov and L. M. Magat:Phys. Met. Metallogr.67 (1989)
[18]S. Mitani, K. Takanashi, M. Sano, H. Fujimori, A. Osawa and H.Nakajima:J. Magn. Magn. Mater.148 (1995)
[19]H. Kanazawa, G. Lauhoff and T. Suzuki:J. Appl. Phys.87 (2000)
[20]S. Okamoto, N. Kikuchi, O. Kitakami, T. Miyazaki, Y. Shimada and K. Fukamichi:Phys. Rev. B 66 (2002)
[21]C. L. Platt,a) K. W. Wierman, E. B. Svedberg, R. van de Veerdonk, and J. K. Howard, A. G. Roy and D. E. Laughlin, J. Appl. Phys.,92.10 (2002)
[1]R. Victora and X. Shen, IEEE Trans. Magn.41,537 (2005)
[2]D. Suess, T.Schrefl, S. Fahler, M. Krischner G. Hrkac, F. Dofbauer and J. Fiedler, Appl. Phys. Lett.87,012504 (2005)
[3]Z. Lu, P. B. Visscher and W. H. Butler, IEEE Trans. Magn.43,2941 (2007)
[4]J. G. Th. Te Lintelo and J. C. Lodder, J. Appl. Phys.77 (1995)
[5]R. W. Chantrll, M. Fearon, E. P. Wohlfarth, Phys. Stat. Sol.97 (1986)
[6]A. M. de Witte, K. O'Grady, G. N. Coverdale, R. W. Chantrell, J. Magn. Magn. Mater.88(1990)
[7]G. B. Ferguson, K. O'Grady, J. Popplewell, R. W. Chantrell, IEEE Trans. Magn. 25 (1989)
[8]M. P. Sharrock, J.Appl. Phys.76,6413 (1994)
[9]M. Kpoor, R. H. Victoria, IEEE Trans. Magn.43,2289 (2007)
[10]J. Dean, M. A. Bashir, A. Goncharov, G. Hrkac, S. Bance, T. Schrefl, A. Cazacu, M. Gubbins, R. W. Lamberton, D. Suess, Appl. Phys. Lett.92 142505 (2008)
[11]S. Kang, Z. Jia, D. E. Nikles, J. W. Harrell, IEEE Trans. Magn,39,2753 (2003)
[12]A. Sebt, M. Akhavan, J. Magn. Magn. Mater.237 (2001)
[13]L. Breth et al, IEEE Trans. Magn.471549 (2011)
[1]Bravman, et al., Mater. Res. Soc. Proc.115, Pittsburgh, PA USA p.179 (1987).
[2]R. M. Anderson, et al., Microscopy of Semiconducting Materials (1989) Proceedings of the Physics Conference held at Oxford University,10-13 April 1989, ed. by Cullis, A. G. andHutchison J. L., Institute of Physics Conference Series Number 100, Bristol and New York (1989)
[3]Benedict, J.P. et al., EMSA Bulletin,19,2, p.74,1989.Klepeis, S. J., et al., EMSA Proceedings, ed. by Bailey, G.W., San Francisco Press, p.712 (1989)
[4]Benedict, J.P., et al., in International Symposium onElectron Microscopy, ed. by Kuo, K. and Yao, J., World Scientific, p.450 (1990)
[5]Benedict, J., et al., in Specimen Preparation for Transmission Electron Microscopy ofMaterials-Ⅱ, ed. Anderson, R., Mater. Res. Soc. Proc.199, Pittsburgh, PA USA p. 189(1990)
[6]Benedict, J. et al. in Specimen Preparation for Transmission Electron Microscopy of Materials-Ⅲ, ed. Anderson et al., Mater. Res. Soc. Proc.254, Pittsburgh, PA USA p.121(1992)
[7]Anderson, R. in Specimen Preparation for Transmission Electron Microscopy of Materials-Ⅲ, ed. Anderson, et al., Mater. Res. Soc. Proc.254, Pittsburgh, PA USA p. 141 (1992)
[8]Anderson, R., et al., Microbeam Analysis (1995) Proceedings of the 29th Annual Meeting of the Microbeam Analysis Society, ed. E. Etz,p.135(1995)
[9]Anderson, R. et.al., in Specimen Preparation for Transmission Electron Microscopy of Materials-IV, ed. Anderson, et al., Mater. Res. Soc. Proc.480, Pittsburgh, PA USA p.187 (1997)
[10]Anderson, R. et.al., in Specimen Preparation for Transmission Electron Microscopy of Materials-IV, ed. Anderson, et al., Mater. Res. Soc. Proc.480, Pittsburgh, PA USA p.193 (1997)
[11]Benedict, J. et al., in "Microscopy and Microanalysis," the Proceedings of the Microscopy Society of America and the Microbeam Analysis Society, Cleveland, OH., USA, Vol 3, Suppl.,2, Springer, p.339 (1997).
[12]Z. R. Dai, Shouheng Sun, Z.L. Wang, Nano. Letterns 1,8 (2001)
[13]C. Y. You, Y. K. Takahashi, K. Hono, J.Appl. Phys.100,056105 (2006)
[14]Liu Xi, Ishio Shunji, Chin. Phys. B 22,8 (2013)
[15]Zhihong Lu, "magnetic anisotropy graded media and Fe-Pt alloy thin films" Ph.D Dissertation (The University of Alabama,2009)。
[2]http://www-03.ibm.com/ibm/history/exhibits/storage/storage_fifty2.html
[3]J-Ulrich Thiele, Magnetic Recording, IEEE magnetic summer school, Nanjing.
[4]M. H. Kryder, and R. W. Gustafson, J. Magn. Magn. Mater,287,449 (2005).
[5]Iwasaki, S., Perpendicular magnetic recording[J]. IEEE Transactions on magnetic, (1980)
[6]Sakhrat Khizroev, Dmitri Litvnovi, "Perpendicular Magnetic Recording"
[7]B. Dipert, and L. Hebert, IEEE. Spectrum 30,48 (1993).
[8]P. Pavan, R. Bez, P. Olivo, and E. Zanoni, Proceedings of the IEEE,85,1248 (1997).
[9]R. Bez, E. Camerlenghi, A. Modelli, and A. Visconti, Proceedings of the IEEE, 91,489 (2003).
[10]G. Lawton, Computer,39,16 (2006).
[11]http://en.wikipedia.org/wiki/solid-state_drive
[12]http://embeddedstar.com/weblog/2009/01/25/bitmirco-ssd-idc
[13]http://www.networkworld.com/news/2009/041009-first-512gb-ssd-drive-offered. html.
[14]W. F. Brown, Phys. Rev.130,1677(1963).
[15]J. L. Dormann, D. Fiorani, and E. Tronc, Adv. Chem. Phys.98,283 (1997).
[16]S. Batra, J. D. Hannary, Z. Hong, and J. S. Goldberg, IEEE. Trans. Magn.40,319 (2004).
[17]R. M. Metzger, V. V. Konovalov, M. Sun, T. Xu, G. Zangari, B. Xu, M. Benakli, W. D. Doyle, IEEE Trans. Magn.36,30 (2000).
[18]H. J. Richter, and A. Y. Dobin, J. Magn. Magn. Mater.287,41 (2005).
[19]K. W. Ng, S. H. Leong, Z. Yuan, B. Liu, and Y. Ma, Appl. Phys. Lett.91,172511 (2007).
[20]http://www.mcplive.cn/index.php/article/index/id/11460
[21]R. L. White, R. M. H. Newt, and R. F. W. Pease, IEEE. Trans. Magn.33,990 (1997)
[22]J. Lohau, A. Moser, C. T. Rettner, M. E. Best, and B. D. Terris, Appl. Phys. Lett.79, 990(2001)
[23]J. Moritz, L. Buda, B. Dieny, J. P. Mozieres, R. Veerdonk, T. M. Crawford amd D. Weller, Appl. Phys. Lett.84,1519 (2004).
[24]B. D. Terris, T. Thomson, and F. Hu, Microsyst Technol.13,189 (2007).
[25]S. Y. Chou, P. R. Krauss, W. Zhang, L. Guo, and L. Zhuang, J. Vac. Sci. Technol. 15,2897(1997).
[26]Jianming Zhu and Yiming Wang, IEEE Trans. Magn.46,3 (2010)
[27]Terumitsu Tanaka, Shota Kashiwagi, Yoshitoki Furomoto, Yuto Otsuka and Kimihide Matsuyama, Nanoscale Research Letters 8,461 (2013)
[28]T. Tanaka, A. kato, Y. Furomoto, A. F. Md Nor, Y. Kanai and K. Matsuyama, J. Appl. Phys. 111,07B711 (2012)
[29]Tim Feldman and Garth Gibson,"Shingled Magnetic Recording- Areal Density Increase Requires New Data Management"
[30]http://www.seagate.com/au/en/tech-insights/breaking-areal-density-barriers-with-sea gate-smr-master-ti/ Victora, IEEE Trans Magn 41,537 (2005)
[31]Y. Y. Zou, J. P. Wang, C. H. Hee, and T. C. Chong, Appl. Phys. Lett.82,2473 (2003).
[32]H. J. Richter, IEEE. Trans. Magn.29,2258 (1993).
[33]R. Victora and X. Shen, IEEE Trans. Magn.41,537 (2005).
[34]D. Suess, T.Schrefl, S. Fahler, M. Krischner G. Hrkac, F. Dofbauer and J. Fiedler, Appl. Phys. Lett.87,012504 (2005).
[35]Z. Lu, P. B. Visscher and W. H. Butler, IEEE Trans. Magn.43,2941 (2007).
[36]B. J. Kirby, J. E. Davies, Kai Liu, S. M. Watson, G. T. Zimanyi, R. D. Shull, P. A. Kienzle, and J. A. Borchers, Phys. Rev. B 81,100405 (2010)
[37]Randy K. Dumas, Chaolin Zha, Yeyu Fang, Valentina Bonanni, June W. Lau, Josep Nogues, and Johan Akerman, IEEE Trans. Magn.47,6 (2011)
[38]J. E. Davies, P. Morrow, C. L. Dennis, J. W. Lau, B. Mcmorran, A. Cochran, J. Unguris, R. K. Dumas, P. Greene, and Kai Liu, J. Appl. Phys.109,07B909 (2011)
[39]Zhihong Lu, Junbo Guo, Zhanghua Gan, Yong Liu, Rui Xiong, G. J. Mankey, and W. H. Butler, J. Appl. Phys.113,073912 (2013)
[40]D. Weller et al. IEEE Trans. Magn.36,10 (2000)
[1]李学周,万英超,姜祥祺,杜元成,真空沉积技术,浙江大学出版社,1994.
[2]唐伟忠,薄膜材料制备原理、技术及应用,冶金工业出版社,1998.
[3]R. Y. Umetsu, C. Mitsumata, A. Sakuma, and K. Fukamichi, Trans. Magn. Soc. Jpn. 3,59 (2003).
[4]H. Zijlstra, Rev. Sci. Instrum.41,1241 (1970)
[5]R. Reeves, J. Phys. E 5,547 (1972)
[6]W. Roos, K.A. Hempel, C. Voight, H. Dedericks, R. Schippan, Rev. Sci. Instrum. 51,612(1980)
[7]H. J. Richter, K. A. Hempel, J. Pfeiffer, Rev. Sci. Instrum.59,1388 (1988)
[8]P. J. Flanders, J. Appl. Phys.63,3940 (1988)
[9]Th. Frey, W. Jantz, R. Stibal, J. Appl. Phys.64,6002 (1988)
[10]P. J. Flanders, Rev. Sci. Instrum.61,839 (1990)
[11]K. O'Grady, V. G. Lewis, D. P. E. Dickson, J. Appl. Phys.73,5608 (1993)
[1]S. Okamoto, N. Kikuchi, O. Kitakami, T. Miyazaki, Y. Shimada, and K. Fukamichi, Phys. Rev. B 66,024413 (2002)
[2]R. F. C. Farrow, D. Weller, R. F. Marks, M. F. Toney, S. Hom, G. R. Harp, and A. Cebollada, Appl. Phys. Lett.69,1166 (1996)
[3]Li-Lien Lee, B. K. Cheong,a) D. E. Laughlin, and D. N. Lambeth, Appl. Phys. Lett.67,24(1995)
[4]J. S. Chenand B. C. Lim, J. F. Hu, Y. K. Lim, and B. Liu, G. M. Chow, Appl. Phys. Lett.90,042508 (2007)
[5]P. Ho, G. C. Han,2 G. M. Chow,l and J. S. Chen,Appl. Phys. Lett.98,252503 (2011)
[6]T. Shimaa) and K. Takanashi,Y. K. Takahashi and K. Hono, Appl. Phys. Lett.85, 13 (2004)
[7]W.B. Mi, J. Jin, H.L. Bai,Journal of Alloys and Compounds 509 (2011)
[8]E. Yang and D. E. Laughlin, J. Appl. Phys.104 (2008)
[9]Z. L. Zhao, J. S. Chen, J. Ding, J. B. Yi, and B. H. Liu, J. P. Wang, Appl. Phys. Lett.88,052503 (2003)
[10]Y.K. Takahashia, K. Honoa, T. Shimab, K. Takanashi, Journal of Magnetism and Magnetic Materials 267 (2003)
[11]Y.F. Ding, J.S. Chena,_, E. Liub, L. Li, Journal of Magnetism and Magnetic Materials 303 (2006)
[12]Y. Zhang,a) J. Wan, V. Skumryev,b) S. Stoyanov, Y. Huang, and G. C. Hadjipanayis, D. Weller, Appl. Phys. Lett.85,22 (2004)
[13]B. D. Cullity, Elements of X-ray diffraction (Addison-Wesley Publishing Company, Inc., (1978)
[14]B. D. Cullity, Elements of X-ray diffraction (Addison-Wesley Publishing Company, Inc., (1978)
[15]O.A. Ivanov, L. V. Solina, V. A. Demshina, and L. M. Magat, Fiz. Met. Metalloved,35,92(1973)
[16]K. Coffey, M. A. Parker, and J. K. Howard, IEEE Trans. Magn.31,2737 (1995)
[17]V. V. Maykov, A. Ye. Yermakov, G. V. Ivanov, V. I. Khrabrov and L. M. Magat:Phys. Met. Metallogr.67 (1989)
[18]S. Mitani, K. Takanashi, M. Sano, H. Fujimori, A. Osawa and H.Nakajima:J. Magn. Magn. Mater.148 (1995)
[19]H. Kanazawa, G. Lauhoff and T. Suzuki:J. Appl. Phys.87 (2000)
[20]S. Okamoto, N. Kikuchi, O. Kitakami, T. Miyazaki, Y. Shimada and K. Fukamichi:Phys. Rev. B 66 (2002)
[21]C. L. Platt,a) K. W. Wierman, E. B. Svedberg, R. van de Veerdonk, and J. K. Howard, A. G. Roy and D. E. Laughlin, J. Appl. Phys.,92.10 (2002)
[1]R. Victora and X. Shen, IEEE Trans. Magn.41,537 (2005)
[2]D. Suess, T.Schrefl, S. Fahler, M. Krischner G. Hrkac, F. Dofbauer and J. Fiedler, Appl. Phys. Lett.87,012504 (2005)
[3]Z. Lu, P. B. Visscher and W. H. Butler, IEEE Trans. Magn.43,2941 (2007)
[4]J. G. Th. Te Lintelo and J. C. Lodder, J. Appl. Phys.77 (1995)
[5]R. W. Chantrll, M. Fearon, E. P. Wohlfarth, Phys. Stat. Sol.97 (1986)
[6]A. M. de Witte, K. O'Grady, G. N. Coverdale, R. W. Chantrell, J. Magn. Magn. Mater.88(1990)
[7]G. B. Ferguson, K. O'Grady, J. Popplewell, R. W. Chantrell, IEEE Trans. Magn. 25 (1989)
[8]M. P. Sharrock, J.Appl. Phys.76,6413 (1994)
[9]M. Kpoor, R. H. Victoria, IEEE Trans. Magn.43,2289 (2007)
[10]J. Dean, M. A. Bashir, A. Goncharov, G. Hrkac, S. Bance, T. Schrefl, A. Cazacu, M. Gubbins, R. W. Lamberton, D. Suess, Appl. Phys. Lett.92 142505 (2008)
[11]S. Kang, Z. Jia, D. E. Nikles, J. W. Harrell, IEEE Trans. Magn,39,2753 (2003)
[12]A. Sebt, M. Akhavan, J. Magn. Magn. Mater.237 (2001)
[13]L. Breth et al, IEEE Trans. Magn.471549 (2011)
[1]Bravman, et al., Mater. Res. Soc. Proc.115, Pittsburgh, PA USA p.179 (1987).
[2]R. M. Anderson, et al., Microscopy of Semiconducting Materials (1989) Proceedings of the Physics Conference held at Oxford University,10-13 April 1989, ed. by Cullis, A. G. andHutchison J. L., Institute of Physics Conference Series Number 100, Bristol and New York (1989)
[3]Benedict, J.P. et al., EMSA Bulletin,19,2, p.74,1989.Klepeis, S. J., et al., EMSA Proceedings, ed. by Bailey, G.W., San Francisco Press, p.712 (1989)
[4]Benedict, J.P., et al., in International Symposium onElectron Microscopy, ed. by Kuo, K. and Yao, J., World Scientific, p.450 (1990)
[5]Benedict, J., et al., in Specimen Preparation for Transmission Electron Microscopy ofMaterials-Ⅱ, ed. Anderson, R., Mater. Res. Soc. Proc.199, Pittsburgh, PA USA p. 189(1990)
[6]Benedict, J. et al. in Specimen Preparation for Transmission Electron Microscopy of Materials-Ⅲ, ed. Anderson et al., Mater. Res. Soc. Proc.254, Pittsburgh, PA USA p.121(1992)
[7]Anderson, R. in Specimen Preparation for Transmission Electron Microscopy of Materials-Ⅲ, ed. Anderson, et al., Mater. Res. Soc. Proc.254, Pittsburgh, PA USA p. 141 (1992)
[8]Anderson, R., et al., Microbeam Analysis (1995) Proceedings of the 29th Annual Meeting of the Microbeam Analysis Society, ed. E. Etz,p.135(1995)
[9]Anderson, R. et.al., in Specimen Preparation for Transmission Electron Microscopy of Materials-IV, ed. Anderson, et al., Mater. Res. Soc. Proc.480, Pittsburgh, PA USA p.187 (1997)
[10]Anderson, R. et.al., in Specimen Preparation for Transmission Electron Microscopy of Materials-IV, ed. Anderson, et al., Mater. Res. Soc. Proc.480, Pittsburgh, PA USA p.193 (1997)
[11]Benedict, J. et al., in "Microscopy and Microanalysis," the Proceedings of the Microscopy Society of America and the Microbeam Analysis Society, Cleveland, OH., USA, Vol 3, Suppl.,2, Springer, p.339 (1997).
[12]Z. R. Dai, Shouheng Sun, Z.L. Wang, Nano. Letterns 1,8 (2001)
[13]C. Y. You, Y. K. Takahashi, K. Hono, J.Appl. Phys.100,056105 (2006)
[14]Liu Xi, Ishio Shunji, Chin. Phys. B 22,8 (2013)
[15]Zhihong Lu, "magnetic anisotropy graded media and Fe-Pt alloy thin films" Ph.D Dissertation (The University of Alabama,2009)。