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Effect of Nd Content on the Structure and Magnetic Properties of Si(111)/Cr/Nd-Co/Cr Thin Films Prepared by Magnetron Sputtering |
HE Xianmei1,TONG Liuniu2(),GAO Cheng2,WANG Yichao2 |
1. School of Mathematics and Physics, Anhui University of Technology, Ma'anshan 243002, China 2. School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan 243002, China |
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Cite this article:
HE Xianmei, TONG Liuniu, GAO Cheng, WANG Yichao. Effect of Nd Content on the Structure and Magnetic Properties of Si(111)/Cr/Nd-Co/Cr Thin Films Prepared by Magnetron Sputtering. Acta Metall Sin, 2019, 55(10): 1349-1358.
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Abstract A series of Si(111)/Cr(10 nm)/NdCox(400 nm)/Cr(10 nm) thin films with the atomic ratio of Co/Nd (x) varying from 2.5 to 7.2 were prepared by radio frequency magnetron sputtering. The influence of Nd content on the structure and magnetic properties of the as-prepared and post annealed films were investigated by XRD, SEM, VSM and AFM/MFM. Magnetic measurements at room temperature show that the compositional variation of the perpendicular anisotropy energy (Ku) exhibits a broad peak around x=5.2 with maximum of Ku=(80±5) kJ/m3 for the as-prepared Nd-Co amorphous films. MFM characterization shows that the root mean square deviation of phase shift in MFM images (Δ?rms) also have a compositional dependence which is similar to that of Ku-x. The experimental results show that the stress induced magneto-elastic anisotropy is the primary origin of the perpendicular magnetic anisotropy (PMA) in the as-prepared Nd-Co amorphous film. After rapid thermal annealing (RTA) process in a vacuum atmosphere at 600 °C, intermetallic compounds such as Nd2Co17, Nd4Co3 and NdCo2 are precipitated in all the studdied films, while NdCo5±x nanocrystals accompanied by the precipitation of Nd2Co7 symbiotic phase were observed only in the films with x=2.5 and 3.8 (the atomic fraction of Nd excesses at least 4%). The in-plane coercivity of the films with x=2.5 and 3.8 was significantly enhanced (Hc-in=54, 51 kA/m) due to the precipitation of NdCo5±x and Nd2Co7 nanocrystals, while that of the samples with x>4.4 remained low value (Hc-in=4~8 kA/m).
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Received: 30 October 2018
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Fund: Supported by National Natural Science Foundation of China(51671001) |
[1] | Bhatti S, Sbiaa R, Hirohata A ,et al. Spintronics based random access memory: A review [J]. Mater. Today, 2017, 20: 530 | [2] | Wang M X, Cai W L, Cao K H, et al. Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance [J]. Nat. Commun., 2018, 9: 671 | [3] | Dai B, Guo Y, Zhu J Q, et al. Spin transfer torque switching in exchange-coupled amorphous GdFeCo/TbFe bilayers for thermally assisted MRAM application [J]. J. Phys., 2017, 50D: 135005 | [4] | Nakayama M, Kai T, Shimomura N ,et al. Spin transfer switching in TbCoFe/CoFeB/MgO/CoFeB/TbCoFe magnetic tunnel junctions with perpendicular magnetic anisotropy [J]. J. Appl. Phys., 2008, 103: 07A710 | [5] | Zhang W Y, Shima H, Takano F, et al. Origin of perpendicular magnetic anisotropy and evolution of magnetic domain structure of amorphous Pr-TM-B (TM=Fe, Co) films [J]. J. Magn. Magn. Mater., 2010, 322: 900 | [6] | Hansen P, Raasch D, Mergel D. Magnetic and magneto-optical properties of amorphous rare earth-transition-metal alloys containing Pr, Nd, Fe, Co [J]. J. Appl. Phys., 1994, 75: 5267 | [7] | Anjum S, Rafique M S, Khaleeq-ur-Rahman M ,et al. Magnetic and optical properties of amorphous NdFeCo thin films by pulsed laser deposition technique [J]. Vacuum, 2010, 85: 126 | [8] | Xi L, Li X Y, Zhou J J ,et al. Influence of magnetic annealing on high-frequency magnetic properties of FeCoNd films [J]. Mater. Sci. Eng., 2011, B176: 1317 | [9] | Chaudhari P, Cuomo J J, Gambino R J. Amorphous metallic films for magneto-optic applications [J]. Appl. Phys. Lett., 1973, 22: 337 | [10] | Suzuki Y, Takayama S, Kirino F ,et al. Single ion model for perpendicular magnetic anisotropy in RE-TM amorphous films [J]. IEEE Trans. Magn., 1987, 23: 2275 | [11] | Fu H, Mansuripur M, Meystre P. Generic source of perpendicular anisotropy in amorphous rare-earth-transition-metal films [J]. Phys. Rev. Lett., 1991, 66: 1086 | [12] | Harris V G, Pokhil T. Selective-resputtering-induced perpendicular magnetic anisotropy in amorphous TbFe films [J]. Phys. Rev. Lett., 2001, 87: 067207 | [13] | Harris R, Pilschke M, Zukermann M J. New model for amorphous magnetism [J]. Phys. Rev. Lett., 1973, 31: 160 | [14] | Cid R, Rodríguez-Rodríguez G, álvarez-Prado L M ,et al. Temperature dependence of the anisotropy of amorphous NdCo5 thin films [J]. J.Magn. Magn. Mater., 2007, 316: e446 | [15] | Cid R, Díaz J, álvarez-Prado L M ,et al. Microscopic origin of perpendicular magnetic anisotropy in amorphous Nd-Co homogeneous and compositionally modulated, thin films studied by XMCD [J]. J. Phys., 2010, 200: 072017 | [16] | Ohta M, Yamada K, Satake Y ,et al. Origin of perpendicular magnetic anisotropy in Tb-Fe amorphous alloy [J]. Mater. Trans., 2003, 44: 2605 | [17] | Xi L, Lu J M, Zhou J J ,et al. Thickness dependence of magnetic anisotropic properties of FeCoNd films [J]. J. Magn. Magn. Mater., 2010, 322: 2272 | [18] | Yu Y X, Yang Y R, Shan Y J, et al. Abnormal substrate temperature dependent out-of-plane anisotropy in FeCoNbB amorphous films [J]. Appl. Phys. Lett., 2012, 101: 232408 | [19] | Tong L N, Li T T, He X M ,et al. The effects of the growth pressure and annealing conditions on perpendicular magnetic anisotropy of sputtered NdFeCo films on Si (111) [J]. J. Alloys Compd., 2014, 605: 149 | [20] | Tong L N, Deng P, He X M ,et al. Abnormal effect of substrate temperature on perpendicular magnetic anisotropy in sputter-deposited NdFeCo films on silicon substrates [J]. Thin Solid Films, 2014, 562: 543 | [21] | Sharma P, Kimura H, Inoue A. Observation of unusual magnetic behavior: Spin reorientation transition in thick Co-Fe-Ta-B glassy films [J]. J. Appl. Phys., 2006, 100: 083902 | [22] | Hubert A, Sh?fer R. Magnetic Domains: The Analysis of Magnetic Microstructures [M]. Berlin: Springer, 1998: 238 | [23] | Co?son M, Celegato F, Olivetti E ,et al. Stripe domains and spin reorientation transition in Fe78B13Si9 thin films produced by RF sputtering [J]. J. Appl. Phys., 2008, 104: 033902 | [24] | Xia A L, Zhang H L, Tong L N ,et al. Lattice mismatch induced weak perpendicular anisotropy in Fe/Co multilayers prepared by direct current magnetron sputtering [J]. Thin Solid Films, 2008, 516: 7653 | [25] | Johnson M T, Bloemen P J H, Den Broeder F J A ,et al. Magnetic anisotropy in metallic multilayers [J]. Rep. Prog. Phys., 1996, 59: 1409 | [26] | Hamann J E, Mohanan S, Herr U. A method for applying a large persistent in-plane biaxial stress to influence the perpendicular magnetic anisotropy of magnetic thin films [J]. J. Appl. Phys., 2007, 102: 113910 | [27] | Jeong J R, Kim Y S, Shin S C. Origins of perpendicular magnetic anisotropy in Ni/Pd multilayer films [J]. J. Appl. Phys., 1999, 85: 5762 | [28] | Dai D S, Qian K M. Ferromagnetism (Book 1) [M]. 2nd Ed., Beijing: Science Press, 2018: 174 | [28] | (戴道生, 钱昆明. 铁磁学(上册) [M]. 第2版. 北京: 科学出版社, 2018: 174) | [29] | Hierro-Rodriguez A, Cid R, Vélez M, et al. Topological defects and misfit strain in magnetic stripe domains of lateral multilayers with perpendicular magnetic anisotropy [J]. Phys. Rev. Lett., 2012, 109: 117202 | [30] | Taylor R C, McGuire T R, Coey J M D ,et al. Magnetic properties of amorphous neodymium-transition-metal films [J]. J. Appl. Phys., 1976, 49: 2885 | [31] | Akdogan N G, Li W F, Hadjipanayis G C. Novel NdCo5 nanoflakes and nanoparticles produced by surfactant-assisted high-energy ball milling [J]. J. Nanopart. Res., 2012, 14: 719 | [32] | Seifert M, Schultz L, Neu V. Magnetization processes and spin reorientation in epitaxial NdCo5±x thin films [J]. J. Appl. Phys., 2009, 106: 073915 | [33] | Seifert M, Schultz L, Neu V. Investigation of the c-axis and basal plane anisotropy in epitaxial NdCo5 thin films [J]. J. Appl. Phys., 2010, 107: 09A711 | [34] | Yang Y Q, Rao G H, Wang T ,et al. Effects of Fe substitution on structural and magnetic properties of the Nd2Co7-xFexcompounds [J]. J. Alloys Compd., 2010, 506: 766 | [35] | Liu X B, Du Z M, Guo C P ,et al. Thermodynamic assessment of the Co-Nd system [J]. J. Alloys Compd., 2007, 439: 97 |
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