Development of High Energy Thin Layers of Exchange Spring Magnets Originating from Rare Earth Magnets of NdFeB/FeCo

Authors

Department of Materials Engineering, Malek Ashtar University of Technology, Shahin Shahr, Iran

Abstract

In this study, nine Nd-Fe-B and FeCe thin films with 10-50 nanometers width were prepared by RF magnetron sputtering on the Si/SiO2 substrate. Then, the films were annealed at 800 oC for 5 sec in rapid thermal annealing furnace. X-ray diffractometry (XRD) was used to analyze the phase composition of layers and existance of Nd2F14 and Fe65Co35 phase was confirmed, without formation of any other secondary phase. The layers surfaces were investigated using Field Emission Scanning Electron Microscope (FESEM). The morphology of layers surfaces was investigated using Atomic Force Microscope (AFM). The magnetic properties of layers were evaluated by vibrating sample magnetometer with maximum applied field of 24kOe, in order to measure coercivity, saturation of magnetization, hysteresis area, rectangular ratio and (BH)max. It was found that all layers have vertical magnetic anisotropy. Increasing thickness of FeCo resulted in increasing saturation of magnetization,  coercivity and saturation magnetization. The results indicate that by an increase in thickness of FeCo up to 20nm, exchange interaction strength between hard and soft magnetic layers is enhanced and, consequently, maximum energy induced from this hetero-structure is increased.

Keywords


1. Kim, D. and Hong, J., "Rare Earth Free Exchange Spring Magnet FeCo/FePt(001): Giant Magnetic Anisotropy and Energy Product", Surface Science, Vol. 606, pp.1960-1964, 2012.
2. Carbucicchio, M. and Ciprian, R., "Influence of the Phenomena Occurring at the Soft/Hard Interface on the Coercivity Behavior in Exchange-Spring Magnets", Solid State Communications, Vol. 152, pp.189-193, 2012.
3. Hoang Hai, N., Chau, N., Duc-The, N. and Thi Hong Gam, D., "Anomalous Magnetic Viscosity in
α-Fe(Co)/(Nd,Pr)2Fe14B Exchange-Spring Magnet", Journal of Magnetism and Magnetic Materials,
Vol. 323, pp. 3156-3161, 2011.
4. Sharma, P., Waki, J., Kaushik, N., Louzguine-Luzgin, D.V., Kimura, H. and Inoue, A., "High Coercivity Characteristics of FePtB Exchange-Coupled Nanocomposite Thick Film Spring Magnets Produced by Sputtering", ActaMaterialia, Vol. 55, pp. 4203-4212, 2007.
5. Asti, G., Solzi, M. and Ghidini, M., "Reversal Modes of the Multilayer Exchange-Spring Magnet", Journal of Magnetism and Magnetic Materials, Vol. 226-230, pp. 1464-1466, 2001.
6. Jiang, J.S. and Bader, S.D., "Magnetic Reversal
in Thin Film Exchange-Spring Magnets", ScriptaMaterialia, Vol. 47, pp. 563-568, 2002.
7. Yamamoto, H., Takahashi, K. and Hamano, R., "Structure Refinement of I-Al–Pd–Mn Quasi Crystals by IP-Weissenberg Camera Data", Journal of Alloys and Compounds, Vol. 342, pp.159-163, 2002.
8. Duc, N.H. and HuongGiang, D.T., "Discontinuous Spring Magnet-Type Magnetostrictiveterfecohan/ YFeCo Multilayers: A Novel Nanostructured Material Principle for Excellent Magnetic Softness", Journal of Magnetism and Magnetic Materials, Vol. 310, pp. 2459-2465, 2007.
9. Duc, N.H., HuongGiang, D.T. and Chau, N., "Nanostructure and Magnetization Reversal Process in TbFeCo/Yx (FeCo)1−x Spring-Magnet Type Multilayers", Journal of Magnetism and Magnetic Materials, Vol. 282, pp.44-48, 2004.
10. Wetherhold, R.C. and Guerrero, V.H., "Magnetoelastic Interaction in Magnetostrictive Spring-Magnet Multilayers", Journal of Magnetism and Magnetic Materials, Vol. 269, pp. 61–69, 2004.
11. Rui, X., Shield, J.E., Sun, Z., Yue, L., Xu, Y., Sellmyer, D.J., Liu, Z. and Miller, D.J., "High-Energy Product Exchange-Spring FePt/Fe Cluster Nanocomposite Permanent Magnets", Journal of Magnetism and Magnetic Materials, Vol. 305,
pp. 76-82, 2006.
12. Koha, G.H., Kima, H.J., Jeonga, W.C., Oha, J.H. and Parka, J.H., "Fabrication of High Performance 64 kb MRAM", Journal of Magnetism and Magnetic Materials, Vol. 272, pp. 1941-1942, 2004.
13. Mapps, D.J., Chandrasekhar, R., OGrady, K., Cambridge, J., Petford Long, A. and Doole R., "Magnetic Properties of NdFeB Thin Films on Platinum Underlayers", IEEE Transactions on Magnetics, Vol. 33, pp. 3007 - 3009, 1997.
14. Tang. W., ZQ, J., Zhang, J.R., Gu, G., Li, J.M. and Du, Y.W., "Nonequilibrium Phase Transformation of NdFe11Ti Compound During Mechanical Milling", Journal of Magnetism and Magnetic Materials,
Vol. 188, pp. 387–392, 1998.
15. Homburg, H., Sinnemann, T., Methfessel, S., Rosenberg, M. and Gu, B.X., "Sputtered NdFeB-Films of High Coercivity", Journal of Magnetism and Magnetic Materials, Vol. 83, pp. 231-233, 1990.
16. Zasadzinski, J.F., Segre, C.U. and Rippert, E.D., "Magnetic Properties of Er2Fe14B and Nd2Fe14B Thin Films", Journal of Applied Physics, Vol. 61,
pp. 4278, 1987.
17. Lemke, H., Lang, T., Goddenhenrich, T. and Heiden, C., “Micro Patterning of Thin Nd2Fe14B Films”, Journal of Magnetism and Magnetic Materials,
Vol. 148, pp. 426-432, 1995.
18. Yu, M., Liu, Y., Liou, S.H. and Sellmyer, D.J., "Nanostructured NdFeB Films Processed by Rapid Thermal Annealing", Journal of Applied Physics, Vol.83, pp.6611 – 6613, 1998.
19. Keavney, D.J., Fullerton, E.E., Pearson, J.E. and Bader, S.D., "Magnetic Properties of C-axis Textured Nd2Fe14B Thin Films", IEEE Transactions on Magnetics, Vol. 32, pp. 4440 – 4442, 1996.
20. Liu, W. and Zhang, Z.D., "Exchange Coupling and Remanence Enhancement in Nanocomposite Multilayer Magnets", Advanced Materials, Vol. 14, pp. 1832–1836, 2002.
21. Liu, W. and Zhang, Z.D., "Structure and Magnetic Properties of Sputtered (Nd,Dy)(Fe,Co,Nb,B)5.5/M (M=FeCo,Co) Multilayer Magnets", Journal of Applied Physics, Vol. 91, pp. 7890 -7892, 2002.

ارتقاء امنیت وب با وف ایرانی