Journal of Interfaces, Thin Films, and Low dimensional systems

The structure of L10-FePt nanoparticles in the presence of Ag

Document Type : Original Article

Authors

Department of Physics, Science and Research Branch, Islamic Azad University, Tehran, Iran

Abstract

Temperature above 600°C during the fabrication process is required to form the L10 compound ordering phase in FePt nanoparticles. The L10-FePt nanoparticles are ferromagnetic with high magnetic anisotropy. Practically, another ordering that is required is the orientation of their crystal c axis perpendicular to the plane of the nanolayer. The effects of the presence of Ag in reducing the transition temperature and making FePt nanocrystals in the L10-FePt phase aligned, in this work, have been studied and determined. The results of XRD analysis indicate that in fabrication using the co-sputtering method, firstly, the presence of Ag before annealing gives rise to the decline of the c parameter of the crystal lattice. This result of XRD analysis has been compared with the result of the RKKY exchange interaction model as an experimental confirmation of this model. Secondly, during annealing, with the formation of FePt-Ag nanostructure, the easy axis of FePt nanoparticles in the L10-FePt phase appears parallel to each other. These results, which are the consequence of the presence of Ag, are obtained by studying FE-SEM images, XRD patterns, and magnetic characterization.

Keywords

Main Subjects

Article Title [Persian]

ساختار نانو ذرات L10-FePt در حضور نقره

Authors [Persian]

  • محمدرضا صلاح پور
  • سید علی سبط
  • آنا خواجه نژاد

گروه فیزیک، دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران، ایران.

Abstract [Persian]

برای تشکیل فاز منظم ترکیبی L10 در نانو ذرات FePt، دمای بالای 600 درجه سانتیگراد در طی فرآیند ساخت لازم است. نانو ذرات L10-FePt، فرومغناطیس با ناهمسانگردی مغناطیسی بالا هستند. به لحاظ عملی، نظم دیگری که مورد نیاز است، جهت گیری محور c بلوری آن ها به طور عمود بر صفحه نانو لایه است. در این کار، اثرات حضور Ag در کاهش دمای گذار و هم راستا کردن نانو بلورهای FePt در فاز L10-FePt، مطالعه و تعیین شده است. نتایج آنالیز XRD نشان می دهند که در ساخت با استفاده از روش کندوپاش همزمان، اولا، حضور Ag قبل از گرمادهی موجب کاهش پارامتر c شبکه بلوری می شود. این نتیجه آنالیز XRD، با نتیجه مدل برهم کنش تبادلی RKKY به عنوان یک تایید تجربی این مدل مقایسه شده است. ثانیا، در طی گرمادهی، با تشکیل نانو ساختار FePt-Ag، محور آسان نانو ذرات FePt در فاز L10-FePt، موازی با یکدیگر ظاهر می شوند. این نتایج که پیامد حضور Ag می باشند، از مطالعه تصاویر FE-SEM، طرح های XRD و مشخصه مغناطیسی به دست می آیند.

Keywords [Persian]

  • نانو ذرات L10-FePt
  • جهت گیری
  • کندوپاش همزمان
  • برهم کنش RKKY
[1] S. Bahamida, A. Fnidiki, M. Coisson, G. Barrera, F. Celegato, E. S. Olivetti, P. Tiberto, A. Laggoun, M. Boudissa, “Effect of the A1 to L10 transformation on the structure and magnetic properties of polycrystalline Fe56 Pd44 alloy thin films produced by thermal evaporation technique.” Thin Solid Films, 668 (2018) 9.
[2] P. Ravindran, A. Kjekshus, H. Fjellvag, P. James, L. Nordstrom, B. Johansson, O. Eriksson, “Large magnetocrystalline anisotropy in bilayer transition metal phases from first-principles full-potential calculations.” Physical Review B, 63 (2001) 144409.
[3] S. A. Khan, P. Blaha, H. Ebert, J. Minar, O. Sipr, “Magnetocrystalline anisotropy of FePt: A detailed view.” Physical Review B, 94 (2016) 144436.
[4] T. Burkert, O. Eriksson, S. I. Simak, A. V. Ruban, B. Sanyal, L. Nordstrom, J. M. Wills, “Magnetic anisotropy of L10 FePt and Fe1-xMnxPt.” Physical Review B, 71 (2005) 134411.
[5] O. N. Mryasov, “Magnetic interactions and phase transformations in FeM, M = (Pt, Rh) ordered alloys.” Phase Transitions, 78 (2005) 197.
[6] M. D. Stiles, “Interlayer exchange coupling.” Journal of Magnetism and Magnetic Materials, 200 (1999) 322.
[7] P. Wahl, P. Simon, L.Diekhoner, V. S. Stepanyuk, P. Bruno, M. A. Schneider, K. Kern, “Exchange interaction between single magnetic adatoms.” Physical Review Letters, 98 (2007) 056601.
[8] J. Wiebe, L. Zhou, R. Wiesendanger, “Atomic magnetism revealed by spin-resolved scanning tunnelling spectroscopy.” Journal of Physics D: Applied Physics, 44 (2011) 464009.
[9] D. A. Gilbert, L. W. Wang, T. J. Klemmer, J. U. Thiele, C. H. Lai, K. Liu, “Tuning magnetic anisotropy in (001) oriented L10 (Fe1-xCux)55Pt45 films.” Applied Physics Letters, 102 (2013) 132406.
[10] G. Varvaro, S. Laureti, D. Fiorani, “L10 FePt-based thin films for future perpendicular magnetic recording media.” Journal of Magnetism and Magnetic Materials, 368 (2014) 415.
[11] M. Ohtake, M. Nakamura, M. Futamoto, F. Kirino, N. Inaba, “Enhancement of L10 ordering with the c-axis perpendicular to the substrate in FePt alloy film by using an epitaxial cap-layer.” AIP ADVANCES, 7 (2017) 056320.
[12] S. Singh, C. L. Prajapat, M. Gupta, S. Basu, “Room temperature Superparamagnetism in ternary (Fe50Pt50)0.42Cu0.58 phase at interfaces on annealing of Fe50Pt50/Cu multilayer.” Journal of Magnetism and Magnetic Materials, 462 (2018) 58.
[13] Y. C. Lai, Y. H. Chang, Y. C. Chen, C. H. Liang, “Inductive magnetization of low-temperature ordered L10-FePt with CoAg underlayer.” Journal of Applied Physics, 101 (2007) 053913.
[14] R. Moradi, S. A. Sebt, H. K. Maleh, R. Sadeghi, F. Karimi, A. Bahari, H. Arabi, “Synthesis and application of FePt/CNTs nanocomposite as a sensor and novel amide ligand as a mediator for simultaneous determination of glutathione, nicotinamide adenine dinucleotide and tryptophan.” Physical Chemistry Chemical Physics, 15 (2013) 5888.
[15] S. A. Sebt, H. Ashourifar, M. M. Larijani, “The effect of electron flow on FePt nanoparticles under heat treatment.” Physica Scripta, 85 (2012) 055804.
[16] S. A. Sebt, A. Bakhshayeshi, M. R. Abolhassani, “Magnetic properties of core / shell nanoparticles with magnetic or nonmagnetic shells.” Journal of Statistical Mechanics: Theory and Experiment, 2012 (2012) P09006.
[17] S. Jain, C. Papusoi, R. Admana, H. Yuan, R. Acharya, “Magnetization reversal process and evaluation of thermal stability factor in Cu doped granular L10 FePt films.” Journal of Applied Physics, 123 (2018) 193902.
[18] C. Brombacher, H. Schletter, M. Daniel, P. Matthes, N. Johrmann, M. Maret, D. Makarov, M. Hietschold, M. Albrecht, “FePtCu alloy thin films: Morphology, L10 chemical ordering, and perpendicular magnetic anisotropy.” Journal of Applied Physics, 112 (2012) 073912.
[19] K. Sharma, G. Sharma, M. Gupta, V. R. Reddy, A. Gupta, “Enhancement of L10 transformation in Fe/Pt multilayer by Cu addition.” AIP ADVANCES, 8 (2018) 105118.
[20] M. Maret, C. Brombacher, P. Matthes, D. Makarov, N. Boudet, M. Albrecht, “Anomalous x-ray diffraction measurements of long-range order in (001) - textured L10 FePtCu thin films.” Physical Review B, 86 (2012) 024204.
[21] Y. Liu, Y. Jiang, N. Kadasala, X. Zhang, C. Mao, Y. Wang, H. Liu, Y. Liu, J. Yang, Y. Yan, “Effects of Au content on the structure and magnetic properties of L10-FePt nanoparticles synthesized by the sol-gel method.” Journal of Solid State Chemistry, 215 (2014) 167-170.
[22] I. A. Vladymyrskyi, A. E. Gafarov, A. P. Burmak, S. I. Sidorenko, G. L. Katona, N. Y. Safonova, F. Ganss, G. Beddies, M. Albrecht, Y. N. Makogon, D. L. Beke, “Low-temperature formation of the FePt phase in the presence of an intermediate Au layer in Pt/Au/Fe thin films.” Journal of Physics D: Applied Physics, 49 (2016) 035003.
[23] V. Deepchand, F. M. Abel, V. Tzitzios and G. C. Hadjipanayis, “Chemical synthesis of L10 Fe-Pt-Ni alloy nanoparticles.” AIP ADVANCES, 8 (2018) 056210.
[24] C. H. Lai and C. H. Ho, “Improvement of magnetic properties of FePt nanoparticles by adding Mn.” Journal of Applied Physics, 97 (2005) 10J314.
[25] D. B. Xu, J. S. Chen, T. J. Zhou, G. M. Chow, “Effects of Mn doping on temperature-dependent magnetic properties of L10 FeMnPt.” Journal of Applied Physics, 109 (2011) 07B747.
[26] S. S. Kang, D. E. Nikles, J. W. Harrell, “Synthesis, chemical ordering, and magnetic properties of self-assembled FePt-Ag nanoparticles.” Journal of Applied Physics, 93(2003) 7178.
[27] Y. Zhang, W. Yu, F. Chen, M. Liu, Y. Yu, H. Li, “Effect of Ag underlayer thickness on the microstructure and magnetic properties of L10-FePt films.” Applied Physics A, 110 (2013) 249.
[28] C. Y. You, Y. K. Takahashi, K. Hono, “Particulate structure of FePt thin films enhanced by Au and Ag alloying.” Journal of Applied Physics, 100 (2006) 056105.
[29] B. S. D. C. S. Varaprasad, Y. K. Takahashi, J. Wang, T. Ina, T. Nakamura, W. Ueno, K. Nitta, T. Uruga, K. Hono, “Mechanism of coercivity enhancement by Ag addition in FePt-C granular films for heat assisted magnetic recording media.” Applied Physics Letters, 104 (2014) 222403.
[30] Y. Tokuoka, Y. Seto, T. Kato, S. Iwata, “Effect of Ag addition to L10 FePt and L10 FePd films grown by molecular beam epitaxy.” Journal of Applied Physics, 115 (2014) 17B716.
[31] R. Roghani, S. A. Sebt, A. Khajehnezhad, “The texture ordering in L10-FePt-Ag nanocomposites.” Journal of Theoretical and Applied Physics, 14 (2020) 47.
[32] R. Roghani, S. A. Sebt, A. Khajehnezhad, “High magnetic coercivity of FePt-Ag/MgO granular nanolayers.” Physica C: Superconductivity and its applications, 549 (2018) 15.
[33] H. Wang, P. Shang, J. Zhang, M. Guo, Y. Mu, Q. Li, H. Wang, “One-step synthesis of high-coercivity L10-FePtAg nanoparticles: Effects of Ag on the morphology and chemical ordering of FePt nanoparticles.” Chemistry of Materials, 25 (2013) 2450.
[34] J. M. D. COEY: Magnetism and Magnetic Materials, Cambridge University Press, New York, 2010.
Journal of Interfaces, Thin Films, and Low dimensional systems
Volume 3, Issue 2
June 2020
Pages 297-304