Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/91966
標題: 二次退火對FePt(FeOx)及FePtX(X=Cu,C)複合薄膜之微結構與磁性質影響
Effects of two-steps annealing on microstructure and magnetic properties of FePt(FeOx) and FePtX(X=Cu,C) composite films
作者: 陳柏仁
Po-Ran Chen
關鍵字: 二次退火
two-steps annealing
引用: 參考文獻 [1] J.D.Livingston,Scientific American,pp.80-5(1998). [2] B.Poulsen,U.S.Patent 661,619.(1990) [3] Moser, A., Takano, K., Margulies, D. T., Albrecht, M., Sonobe, Y., Ikeda, Y., ... & Fullerton, E. E. (2002). Magnetic recording: advancing into the future. Journal of Physics D: Applied Physics, 35(19), R157. [4] Suzuki, T., Kiya, T., Honda, N., & Ouchi, K. (2001). Fe–Pt perpendicular double-layered media with high recording resolution. Journal of magnetism and magnetic materials, 235(1), 312-318 [5] Terris, B. D., & Thomson, T. (2005). Nanofabricated and self-assembled magnetic structures as data storage media. Journal of physics D: Applied physics, 38(12), R199. [6] Alex, M., Tselikov, A., Mcdaniel, T., Deeman, N., Valet, T., & Chen, D. (2001). Characteristics of thermally assisted magnetic recording. IEEE transactions on magnetics, 37(4), 1244-1249. [7] Wood, R. (2009). Future hard disk drive systems. Journal of magnetism and magnetic materials, 321(6), 555-561. [8] Goll, D., & Bublat, T. (2013). Large‐area hard magnetic L10‐FePt and composite L10‐FePt based nanopatterns. physica status solidi (a), 210(7), 1261-1271. [9] http://www.nims.go.jp/apfim/GMR.html [10] Charap, S. H., Lu, P. L., & He, Y. (1997). Thermal stability of recorded information at high densities. Magnetics, IEEE Transactions on, 33(1), 978-983. [11] Iwasaki, S. I., & Takemura, K. (1975). An analysis for the circular mode of magnetization in short wavelength recording. Magnetics, IEEE Transactions on,11(5), 1173-1175. [12] http://www.hgst.com/ [13] Litvinov, D., Kryder, M. H., & Khizroev, S. (2001). Recording physics of perpendicular media: soft underlayers. Journal of Magnetism and Magnetic Materials, 232(1), 84-90. [14] Weller, D., Mosendz, O., Parker, G., Pisana, S., & Santos, T. S. (2013). L10 FePtX–Y media for heat‐assisted magnetic recording. physica status solidi (a),210(7), 1245-1260. [15] http://www.seagate.com/tw/zh/ [16] httpwww.seagate.com [17] Kryder, M. H., Gage, E. C., McDaniel, T. W., Challener, W. A., Rottmayer, R. E., Ju, G., ... & Erden, M. F. (2008). Heat assisted magnetic recording.Proceedings of the IEEE, 96(11), 1810-1835. [18] Weller, D., Moser, A., Folks, L., Best, M. E., Lee, W., Toney, M. F., ... & Doerner, M. F. (2000). High K u materials approach to 100 Gbits/in 2.Magnetics, IEEE Transactions on, 36(1), 10-15. [19] Rottmayer, R. E., Batra, S., Buechel, D., Challener, W. A., Hohlfeld, J., Kubota, Y., ... & Yang, X. (2006). Heat-assisted magnetic recording. Magnetics, IEEE Transactions on, 42(10), 2417-2421. [20] Rong, C. B., Li, D., Nandwana, V., Poudyal, N., Ding, Y., Wang, Z. L., ... & Liu, J. P. (2006). Size‐dependent chemical and magnetic ordering in L10‐FePt nanoparticles. Advanced Materials, 18(22), 2984-2988. [21] Hovorka, O., Devos, S., Coopman, Q., Fan, W. J., Aas, C. J., Evans, R. F. L., ... & Chantrell, R. W. (2012). The Curie temperature distribution of FePt granular magnetic recording media. Applied Physics Letters, 101(5), 052406-052406. [22] Lu, H. M., Li, P. Y., Cao, Z. H., & Meng, X. K. (2009). Size-, shape-, and dimensionality-dependent melting temperatures of nanocrystals. The Journal of Physical Chemistry C, 113(18), 7598-7602. [23] Lyberatos, A., Weller, D., Parker, G. J., & Stipe, B. C. (2012). Size dependence of the Curie temperature of L1o-FePt nanoparticles. Journal of Applied Physics, 112(11), 113915. [24] Hansen, M., Anderko, K., & Salzberg, H. W. (1958). Constitution of binary alloys. Journal of the Electrochemical Society, 105(12), 260C-261C. [25] Kawald, U., Zemke, W., Bach, H., Pelzl, J., & Saunders, G. A. (1989). Elastic constants and martensitic phase transitions in FePt and FeNiPt invar alloys.Physica B: Condensed Matter, 161(1), 72-74.. [26] B. E. Warren (1990), X-ray Diffraction, Dover, New York, p. 227. [27] Ostrikov, K. K., Levchenko, I., Cvelbar, U., Sunkara, M., & Mozetic, M. (2010). From nucleation to nanowires: a single-step process in reactive plasmas.Nanoscale, 2(10), 2012-2027.. [28] http://www.geocities.jp/ohba_lab_ob_page/structure6.html [29] http://zh.wikipedia.org/ [30] 金重勳、李景明、張慶瑞(2002),磁性技術手冊,第二章,P.5~7 [31] N. A. Spaldin(2011), Magnetic Material,p.17. [32] Soshin Chikazumi 著, 張煦, 李學養合譯, 磁性物理學 [33] B.D. Cullity(1972), Introduction to magnetic materials, Wesley,ch7. [34] D.E.Gray (1972), McGraw-Hill American Institute of Physics Handbook. [35] M.J. Clerk(1954), Atreatise on Electicity and magnetism, Vol.2.1006. [36] 蕭世男,初始應力/應變態對鐵鉑薄膜其序化轉變與動力學之影響,逢甲大學博士論文,中華民國一百年三月。 [37] Wu, Y. C., Wang, L. W., Lai, C. H., & Chang, C. R. (2008). Control of microstructure in (001)-orientated FePt–SiO 2 granular films. Journal of Applied Physics, 103(7), 07E140-07E140. [38] Lai, C. H., Yang, C. H., Chiang, C. C., Balaji, T., & Tseng, T. K. (2004). Dynamic stress-induced low-temperature ordering of FePt. Applied physics letters, 85(19), 4430-4432. [39] Yang, E., Laughlin, D. E., & Zhu, J. G. (2012). Correction of order parameter calculations for FePt perpendicular thin films. Magnetics, IEEE Transactions on, 48(1), 7-12.. [40] Takanashi, K., Watanabe, M., & Fujimori, H. (1992). Correlation between magnetooptical Kerr rotation and anomalous Hall effect in FePt/Pt multilayer films. Journal of Magnetism and Magnetic Materials, 104, 1749-1750. [41] Visokay, M. R., Lairson, B. M., Clemens, B. M., & Sinclair, R. (1993). Microstructural analysis of magnetic Fe/Pt multilayer thin films by transmission electron microscopy. Journal of magnetism and magnetic materials, 126(1), 136-140. [42] Mitani, S., Takanashi, K., Sano, M., Fujimori, H., Osawa, A., & Nakajima, H. (1995). Perpendicular magnetic anisotropy and magneto-optical Kerr rotation in FePt (001) monoatomic multilayers. Journal of magnetism and magnetic materials, 148(1), 163-164. [43] Hong, M. H., Hono, K., & Watanabe, M. (1998). Microstructure of FePt/Pt magneticthin films with high perpendicular coercivity. Journal of applied physics,84(8), 4403-4409. [44] Suzuki, T., Harada, K., Honda, N., & Ouchi, K. (1999). Preparation of ordered Fe–Pt thin films for perpendicular magnetic recording media. Journal of magnetism and magnetic materials, 193(1), 85-88. [45] Shima, T., Takanashi, K., Takahashi, Y. K., & Hono, K. (2002). Preparation and magnetic properties of highly coercive FePt films. Applied physics letters, 81(6), 1050-1052. [46] Shima, T., Moriguchi, T., Mitani, S., & Takanashi, K. (2002). Low-temperature fabrication of L10 ordered FePt alloy by alternate monatomic layer deposition.Applied physics letters, 80(2), 288-290. [47] Xu, Y., Chen, J. S., & Wang, J. P. (2002). In situ ordering of FePt thin films with face-centered-tetragonal (001) texture on Cr 100-x Ru x underlayer at low substrate temperature. Applied physics letters, 80(18), 3325-3327.   [48] Chen, S. C., Sun, T. H., Shen, C. L., Peng, W. C., Chen, C. D., Kuo, P. C., & Chen, J. R. (2011). Microstructure and Magnetic Properties of In-Situ Deposited FePt Films on MgO (200) Films of Varying Thicknesses. Magnetics, IEEE Transactions on, 47(3), 517-520. [49] Rasmussen, P., Rui, X., & Shield, J. E. (2005). Texture formation in FePt thin films via thermal stress management. Applied Physics Letters, 86(19), 191915. [50] Kim, J. S., Koo, Y. M., Lee, B. J., & Lee, S. R. (2006). The origin of (001) texture evolution in FePt thin films on amorphous substrates. Journal of applied physics, 99(5), 053906. [51] Wu, Y. C., Wang, L. W., & Lai, C. H. (2007). Low-temperature ordering of (001) granular FePt films by inserting ultrathin SiO 2 layers. Applied Physics Letters,91(7), 072502-072502. [52] Wang, L. W., Shih, W. C., Wu, Y. C., & Lai, C. H. (2012). Promotion of [001]-oriented L10-FePt by rapid thermal annealing with light absorption layer. Applied Physics Letters, 101(25), 252403. [53] Mizuguchi, M., Sakurada, T., Tashiro, T. Y., Sato, K., Konno, T. J., & Takanashi, K. (2013). Fabrication of highly L10-ordered FePt thin films by low-temperature rapid thermal annealing. APL Materials, 1(3), 032117. [54] Massalski, T. B., Okamoto, H., Subramanian, P. R., & Kacprzak, L. (1990).Binary alloy phase diagrams. ASM international. [55] Chen, S. C., Kuo, P. C., Sun, A. C., Lie, C. T., & Hsu, W. C. (2002). Granular FePt–Ag thin films with uniform FePt particle size for high-density magnetic recording. Materials Science and Engineering: B, 88(1), 91-97. [56] Zhao, Z. L., Ding, J., Inaba, K., Chen, J. S., & Wang, J. P. (2003). Promotion of L1 0 ordered phase transformation by the Ag top layer on FePt thin films.Applied physics letters, 83(11), 2196-2198. [57] Platt, C. L., Wierman, K. W., Svedberg, E. B., Van de Veerdonk, R., Howard, J. K., Roy, A. G., & Laughlin, D. E. (2002). L–10 ordering and microstructure of FePt thin films with Cu, Ag, and Au additive. Journal of Applied Physics, 92(10), 6104-6109. [58] Yang, T., Ahmad, E., & Suzuki, T. (2002). FePt–Ag nanocomposite film with perpendicular magnetic anisotropy. Journal of applied physics, 91(10), 6860-6862. [59] Zhang, Z., Kang, K., & Suzuki, T. (2003). Magnetic and magneto-optical properties of ultrathin Fe 50 Pt 50 films with Ag layers inserted. Journal of applied physics, 93(10), 7163-7165.   [60] Zhao, Z. L., Chen, J. S., Ding, J., Inaba, K., & Wang, J. P. (2004). The effect of additive Ag layers on the L10 FePt phase transformation. Journal of magnetism and magnetic materials, 282, 105-108. [61] Zhao, Z. L., Ding, J., Yi, J. B., Chen, J. S., Zeng, J. H., & Wang, J. P. (2005). The mechanism of Ag top layer on the coercivity enhancement of FePt thin films. Journal of applied physics, 97(10), 10H502-10H502. [62] Zhao, Z. L., Chen, J. S., Ding, J., Yi, J. B., Liu, B. H., & Wang, J. P. (2006). Fabrication and microstructure of high coercivity FePt thin films at 400 C.Applied physics letters, 88(5), 052503. [63] You, C. Y., Takahashi, Y. K., & Hono, K. (2006). Particulate structure of FePt thin films enhanced by Au and Ag alloying. Journal of applied physics, 100(5), 056105. [64] Zhang, L., Takahashi, Y. K., Perumal, A., & Hono, K. (2010). L10-ordered high coercivity (FePt) Ag–C granular thin films for perpendicular recording. Journal of Magnetism and Magnetic Materials, 322(18), 2658-2664. [65] Chen, J. S., Zhou, Y. Z., Sun, C. J., Han, S. W., & Chow, G. M. (2011). Where is the Ag in FePt–Ag composite films?. Applied Physics Letters, 98(13), 131914. [66] Wen, W. C., Chepulskii, R. V., Wang, L. W., Curtarolo, S., & Lai, C. H. (2012). Accelerating disorder–order transitions of FePt by preforming a metastable AgPt phase. Acta Materialia, 60(20), 7258-7264. [67] Maeda, T., Kai, T., Kikitsu, A., Nagase, T., & Akiyama, J. I. (2002). Reduction of ordering temperature of an FePt-ordered alloy by addition of Cu. Applied physics letters, 80(12), 2147-2149. [68] Lee, S. R., Yang, S., Kim, Y. K., & Na, J. G. (2001). Rapid ordering of Zr-doped FePt alloy films. Applied Physics Letters, 78(25), 4001-4003. [69] Platt, C. L., Wierman, K. W., Svedberg, E. B., Van de Veerdonk, R., Howard, J. K., Roy, A. G., & Laughlin, D. E. (2002). L–10 ordering and microstructure of FePt thin films with Cu, Ag, and Au additive. Journal of Applied Physics, 92(10), 6104-6109. [70] Berry, D. C., & Barmak, K. (2007). Effect of alloy composition on the thermodynamic and kinetic parameters of the A1 to L10 transformation in FePt, FeNiPt, and FeCuPt films. Journal of Applied Physics, 102(2), 024912. [71] Xu, D. B., Chen, J. S., Zhou, T. J., & Chow, G. M. (2011). Effects of Mn doping on temperature-dependent magnetic properties of L10 FeMnPt. Journal of Applied Physics, 109(7), 07B747. [72] Takahashi, Y. K., Ohnuma, M., & Hono, K. (2002). Effect of Cu on the structure and magnetic properties of FePt sputtered film. Journal of magnetism and magnetic materials, 246(1), 259-265. [73] Willoughby, S. D. (2004). Electronic and magnetic properties of Fe 1-x Cu x Pt.Journal of applied physics, 95(11), 6586-6588. [74] Zha, C. L., Dumas, R. K., Fang, Y. Y., Bonanni, V., Nogues, J., & Akerman, J. (2010). Continuously graded anisotropy in single (Fe53Pt47) 100− xCux films.Applied Physics Letters, 97(18), 182504. [75] Gilbert, D. A., Wang, L. W., Klemmer, T. J., Thiele, J. U., Lai, C. H., & Liu, K. (2013). Tuning magnetic anisotropy in (001) oriented L10 (Fe1− xCux) 55Pt45 films. Applied Physics Letters, 102(13), 132406. [76] Wang, J. P., Shen, W., & Hong, S. Y. (2007). Fabrication and characterization of exchange coupled composite media. Magnetics, IEEE Transactions on,43(2), 682-686. [77] Victora, R. H., & Shen, X. (2005). Exchange coupled composite media for perpendicular magnetic recording. Magnetics, IEEE Transactions on, 41(10), 2828-2833. [78] Makarov, D., Lee, J., Brombacher, C., Schubert, C., Fuger, M., Suess, D., ... & Albrecht, M. (2010). Perpendicular FePt-based exchange-coupled composite media. Applied Physics Letters, 96(6), 062501. [79] Guo, H. H., Liao, J. L., Ma, B., Zhang, Z. Z., Jin, Q. Y., Wang, H., & Wang, J. P. (2012). Microstructure and magnetization reversal of L10-FePt/[Co/Pt] N exchange coupled composite films. Applied Physics Letters, 100(14), 142406. [80] Takahashi, Y. K., Seki, T. O., Hono, K., Shima, T., & Takanashi, K. (2004). Microstructure and magnetic properties of FePt and Fe/FePt polycrystalline films with high coercivity. Journal of applied physics, 96(1), 475-481. [81] Liu, J. P., Luo, C. P., Liu, Y., & Sellmyer, D. J. (1998). High energy products in rapidly annealed nanoscale Fe/Pt multilayers. Applied physics letters, 72(4), 483-485. [82] Tsai, J. L., Tzeng, H. T., & Liu, B. F. (2010). Magnetic properties and microstructure of graded Fe/FePt films. Journal of Applied Physics, 107(11), 113923. [83] Goll, D., Breitling, A., Gu, L., Van Aken, P. A., & Sigle, W. (2008). Experimental realization of graded L10-FePt/Fe composite media with perpendicular magnetization. Journal of Applied Physics, 104(8), 083903. [84] Casoli, F., Albertini, F., Nasi, L., Fabbrici, S., Cabassi, R., Bolzoni, F., & Bocchi, C. (2008). Strong coercivity reduction in perpendicular FePt∕ Fe bilayers due to hard/soft coupling. Applied Physics Letters, 92(14), 142506. [85] Zhou, J., Skomski, R., Li, X., Tang, W., Hadjipanayis, G. C., & Sellmyer, D. J. (2002). Permanent-magnet properties of thermally processed FePt and FePt-Fe multilayer films. Magnetics, IEEE Transactions on, 38(5), 2802-2804. [86] Jai-Lin Tsai,, Hsin-Te Tzeng, and Guo-Bin Lin. 'Magnetization reversal process in Fe/FePt films.' Applied Physics Letters 96.3 (2010): 032505. [87] Huang, L. S., Hu, J. F., Chow, G. M., & Chen, J. S. (2013). Annealing effect on the FePt/Fe exchange-coupled granular bilayer. Journal of Applied Physics,114(17), 173903. [88] Liao, J. W., Huang, K. F., Wang, L. W., Tsai, W. C., Wen, W. C., Chiang, C. C., ... & Lai, C. H. (2013). Highly (001)-oriented thin continuous L10 FePt film by introducing an FeOx cap layer. Applied Physics Letters, 102(6), 062420. [89] http://web1.knvs.tp.edu.tw/AFM/ch4.htm [90] http://www.temple.edu/strongin/afm.html [91] 引用資料來源網址” http://www.bruker-axs.com, Bruker AXS” [92] 引用資料來源網址” http://www.lakeshore.com” [93] B. D. Cullity, C. D. Graham(2009), “Introduction to Magnetic Materials”, second edition, p.68. [94] 引用資料來源網址”國立中興大學奈米中心網站” [95] D. B. W. a. C. B. Carter(1996), Transmission Electron Microscopy: Plenum Press, New York and London. [96] 中興大學 校內貴儀 http://www.mse.nchu.edu.tw/pro/property.php?Sn=18 [97] 潘扶民,汪建民”材料分析”中國材料科學學會,第十三章,1998年 [98] 連興隆'XPS X-ray Photoelectron Spectroscopy' [99] 中興大學校內貴重儀器 http://www.mse.nchu.edu.tw/pro/property.php?Sn=21 [100] 清華大學博士-羅聖全'奈米小大世界-電子顯微鏡介紹– SEM' [101] 陳力俊'材料電子顯微鏡學'科儀叢書P.285-318 [102] Cebollada, A., Weller, D., Sticht, J., Harp, G. R., Farrow, R. F. C., Marks, R. F., ... & Scott, J. C. (1994). Enhanced magneto-optical Kerr effect in spontaneously ordered FePt alloys: Quantitative agreement between theory and experiment. Physical Review B, 50(5), 3419. [103] Cowern, N. E. B., Van de Walle, G. F. A., Gravesteijn, D. J., & Vriezema, C. J. (1991). Experiments on atomic-scale mechanisms of diffusion. Physical review letters, 67(2), 212. [104] Hawn, D. D., & DeKoven, B. M. (1987). Deconvolution as a correction for photoelectron inelastic energy losses in the core level XPS spectra of iron oxides. Surface and interface analysis, 10(2‐3), 63-74. [105] D. Brian (1980), Appl. Surf. Sci., Vol. 5, p. 133. [106] Oku M., Hirokawa K. (1976), J. Electron Spectrosc. Relat. Phenom. , Vol. 8, p. 475 [107] Nefedov V.I., Gati D., Dzhurinskii, B.F., Sergushin N.P. (1975), Zh. Neorg. Khimii, Vol. 20, P. 2307 [108] Li, Y. X., & Klabunde, K. J. (1990). Studies of Pt-Sn/Al< sub> 2</sub> O< sub> 3</sub> catalysts prepared by Pt and Sn coevaporation (solvated metal atom dispersion). Journal of Catalysis, 126(1), 173-186. [109] Ye, J., & Thompson, C. V. (2010). Mechanisms of complex morphological evolution during solid-state dewetting of single-crystal nickel thin films. Applied Physics Letters, 97(7), 071904. [110] Clearfield, R., Railsback, J. G., Pearce, R. C., Hensley, D. K., Fowlkes, J. D., Fuentes-Cabrera, M., ... & Melechko, A. V. (2010). Reactive solid-state dewetting of Cu–Ni films on silicon. Applied Physics Letters, 97(25), 253101. [111] Himpsel, F. J., Ortega, J. E., Mankey, G. J., & Willis, R. F. (1998). Magnetic nanostructures. Advances in physics, 47(4), 511-597. [112] Granz, S. D., Barmak, K., & Kryder, M. H. (2013). Granular L10 FePt: X (X= Ag, B, C, SiOx, TaOx) thin films for heat assisted magnetic recording. The European Physical Journal B, 86(3), 1-7. [113] Ohring, M. (2001). Materials science of thin films. Academic press. P.174~175 [114] Chen, J. S., Lim, B. C., Hu, J. F., Liu, B., Chow, G. M., & Ju, G. (2007). Low temperature deposited L1 0 FePt–C (001) films with high coercivity and small grain size. Applied Physics Letters, 91(13), 132506-132506.
摘要: We used two steps annealing to form films with great perpendicular magnetization that could not make with multilayers or co-sputter. The two steps annealing tuned composition of films as a result of enhanced atomic diffusion. The Fe(6 nm)/FePt film with perpendicular magnetization was deposited on the glass substrate. To study the oxygen diffusion effect on the coupling of Fe/FePt bilayer, we flowed 0~10 vol.% oxygen and deposited FeOx(3 nm)/Fe(3 nm)/L10FePt(11 nm) trilayer with plasma oxidation. Two-step magnetic hysteresis loops were found in trilayer that suggested the magnetization reverse of FeOx and Fe/L10FePt were not at the same time. The trilayers were annealed again at 500℃ and 800℃ for 3 minutes. When trilayers were annealed at 500℃, the magnetization reverse was coupled with single switching field and the layer structure changed to FeOx/FePt bilayer due to oxygen diffusion. The out-of-plane coercivity of single FePt was changed from 15.3 kOe to 10.4 kOe for FeOx/FePt bilayer. But further annealed at 800℃, the hysteresis loops presented soft-magnetic loop due to the oxygen was diffused into FePt layer and disordered the L10 phase. In summary, two steps annealing can controll the oxygen diffusion and tune the coupling between soft-magnetic and hard-magnetic layer. In second part, we investigated the C added in FePt layer in order to suppress the grain growth with two step annealing. Multilayers FePt(1 nm)/[Cu(x nm)/Fe(1 nm)]5/C(1 nm)/L10FePt(11 nm) were alternately deposited on a glass substrate, in order to reduce Curie temperture(Tc). The residual magnetization of hard axis was increased by C additive(to 400~500 emu/cm3) but decreased with Cu interleaved(to ~250 emu/cm3). We suggested with the magnetization of Fe arrayed with parallel to films. The specimen was annealed again at 200~600℃ for 3 minutes. The Mr of hard axis declined and Hc of easy axis elevated, and the tendency was promoted in Cu environment due to melting point of films were decreased. The film compositions can be tune with further annealed, the proportion of Fe and Pt change from 52 : 48 to 59.8 : 40.2 due to atomic duffusion. In summary, two step annealing can tune composition of films that improve properties of the films and maintain anisotropy.
此實驗為了製備以多層膜或共鍍方式無法製作的FePt薄膜性值,故利用二次快速升溫退火的方式,讓膜層內部原子交互擴散以及調整膜層的成分,達到微調整體薄膜性質並保持良好之磁晶異向性。此實驗可以分成兩大部分:第一部分為在非晶玻璃基板上製備具良好垂直異向性之Fe(6 nm)/L10FePt(11 nm)薄膜,為了探討氧氣擴散對膜層耦合的影響,通入流量0~10%體積百分率之氧氣形成氧化電漿製備FeOx(3 nm)/Fe(3 nm)/L10FePt(11 nm)三層薄膜,而我們發現當氧氣通入會產生兩階段翻轉之磁滯曲線即FeOx與Fe/L10FePt之磁矩翻轉不一。將樣品進行500℃與800℃3分鐘二次快速退火,在二次退火500℃其氧氣擴散至Fe層形成FeOx(6 nm) /L10FePt(11 nm)之成分梯度薄膜,成功提升交互耦合效果並將垂直矯頑磁力由15.3 kOe(序化FePt)降至10.4kOe(3 vol.% O2),但將二次退火溫度提升至800℃,氧氣會擴散至FePt層破壞轉變為軟磁相FePt。總括可利用二次退火機制使氧氣擴散並提升硬磁層與軟磁層之交互耦合能力。 第二部分以添加C抑制二次退火造成晶粒成長之現象,並將厚度為0.2~1nm Cu與Fe交互穿插形成FePt(1)/[Cu(x)/Fe(1)]5/C(1 nm)/L10FePt(11 nm)複合薄膜,以Cu添加來降低整體膜層的居里溫度。而我們發現水平殘留磁化量會隨著C厚度增加而增加(400~500 emu/cm3)但隨Cu穿插而下降(~250 emu/cm3),此與Fe原子沉積時之排列方向有關,經二次快速退火200~600℃,其水平殘留磁化量隨溫度上升而下降且垂直矯頑磁場會增加,我們也發現此變化在有Cu穿插之樣品會在較低的二次退火溫度(400℃)發生,即在有Cu的環境下整體膜層之熔點下降進而提升擴散速率,而由成分量測也可以得知經二次快速退火其膜層成分會因原子擴散而改變,Fe與Pt之原子比例由原本的52 : 48轉變為59.8 : 40.2。由研究證實二次退火可利用原子擴散達到微調薄膜成分形成成分梯度薄膜或合金化,進而改善FePr基膜層之垂直異向性。
URI: http://hdl.handle.net/11455/91966
其他識別: U0005-2706201411542100
文章公開時間: 2017-07-03
Appears in Collections:材料科學與工程學系

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.