Optimizing Magnetic Performance and Microstructure of CoPt Nanoparticles by Sol-Gel Synthesis

Abstract

We prepared Co_xPt_100−x (x = 40, 45, 50, 55, 60) nanoparticles by the sol-gel method. The phase composition and crystal structure, morphology and microstructure, and magnetic properties of the samples were characterized and tested using X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM), respectively. The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples. Among the compositions studied, the Co₄₅Pt₅₅ sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10⁵ A/m is achieved. The morphology and microstructure of the nanoparticles were analyzed by TEM images, indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.

Keywords

CoPt / sol-gel method / atomic ratio / magnetic nanoparticles / coercivity

References

[1] WANG H, HUANG ZX, WUB, et al. Studies on the Preparation and Magnetic Properties of SmCo/Cr Thin Films with Co-sputtering[J]. Information Recording Materials, 2007(01): 47–50

[2] Cheng HF, Gao ZS, Wang DL, et al.. Development of Ultra-high Density Magnetic Recording Media[J]. Materials Review, 2010, 24(13): 35-3948

[3] He X M, Tong LN, Gao C. Effect of Nd Content on the Structure and Magnetic Properties of Si(111)/Cr/Nd-Co/Cr Thin Films Prepared by Magnetron Sputtering[J]. Acta Metallurgica Sinica, 2019, 55(10): 1 349-1 358

[4] ZHEN CM, MAL, ZHANG JJ, et al. Effect of Ti(Cr) Buffer Layer on the Magnetic Properties and Microstructure of CoCrTa Film for Pre-pendicular Magnetic Recording Media[J]. Acta physica Sinica, 2007 (03): 1 730–1 734

[5] Bertram HN, Williams M. SNR and Density Limit Estimates: A Comparison of Longitudinal and Perpendicular Recording[J]. IEEE Transactions on Magnetics, 2000, 36(1): 4-9

[6] Yu J, Gao WL, Liu F, et al.. Tuning Crystal Structure and Magnetic Property of Dispersible FePt Intermetallic Nanoparticles[J]. Science China-Materials, 2018, 61(7): 961-968

[7] An HY, Harumoto T, Sannomiya T, et al.. Effect of Substrate Temperature on the Structure and Magnetic Properties of CoPt/AlN Multilayer Films[J]. Journal of Wuhan University of Technology-Materials Science Edition, 2016, 31(1): 44-47

[8] Fu ZW, Chen ZH. High Temperature Grain Size and Electromagnetic Properties of FeCo Nanocrystalline Absorber[J]. Journal of Wuhan University of Technology, 2022, 44(08): 1-6

[9] Pan CJ, Gao TH, Itogawa N, et al.. Large Lattice Mismatch Induced Perpendicular Magnetic Anisotropy and Perpendicular Exchange Bias in CoPt/FeMn Bilayer Films[J]. Science China-Technological Sciences, 2019, 62(11): 2 009-2 013

[10] Xia TY, Liu JL, Wang SG, et al.. Nanomagnetic CoPt Truncated Octahedrons: Facile Synthesis, Superior Electrocatalytic Activity and Stability for Methanol Oxidation[J]. Science China-Materials, 2017, 60(1): 57-67

[11] LIAO LL, XU DY. Studies on Synthesis and Effects on Smoke Suppression of Nano-oxides[J]. Chinese Journal of Colloid and Polymer, 2003, (02): 22–24

[12] Zhao YH, Luan XM. Development of Information Recording Materials[J]. Information Recording Materials, 2015, 16(01): 58-64

[13] Ju GP, Peng YG, Chang EKC, et al.. High Density Heat-Assisted Magnetic Recording Media and Advanced Characterization-Progress and Challenges[J]. IEEE Transactions on Magnetics, 2015, 51(11): 1-9

[14] Kryder MH, Gage EC, Mcdaniel TW, et al.. Heat Assisted Magnetic Recording[J]. Proceedings of the IEEE, 2008, 96(11): 1 810-1 835

[15] Weller D, Mosendz O, Parker G, et al.. L1₀FePt_X-Y Media for Heat-assisted Magnetic Recording[J]. Physica Status Solidi a-Applications and Materials Science, 2013, 210(7): 1 245-1 260

[16] Yu ACC, Mizuno M, Sasaki Y, et al.. Structural Characteristics and Magnetic Properties of Chemically Synthesized CoPt Nanoparticles[J]. Applied Physics Letters, 2002, 81(20): 3 768-3 770

[17] Chen M, Nikles DE. Synthesis of Spherical FePd and CoPt Nanoparticles[J]. Journal of Applied Physics, 2002, 91(10): 8 477-8 479

[18] Mandal M, Das B, Mandal K. Synthesis of Co_xPt_1−x Alloy Nanoparticles of Different Phase by Micellar Technique and Their Properties Study[J]. Journal of Colloid and Interface Science, 2009, 335(1): 40-43

[19] Sun GD, Kang X, Jin S, et al.. Synthesis and Structure Determination of Ag-Ni Alloy Nanocluster Ag₄Ni₂(SPhMe₂)₈ (SPhMe₂=2, 4-dimethylbenzenethiol) [J]. Acta Physico-Chimica Sinica, 2018, 34(7): 799-804

[20] Zheng YK, Jiang H, Wang XM. Multiple Strategies for Controlled Synthesis of Atomically Precise Alloy Nanoclusters[J]. Acta Physico-Chimica Sinica, 2018, 34(7): 740-754

[21] Nuengmatcha P, Noypha A, Tangwatanakul W, et al.. Effect of Boron Addition on the Phase-transition Temperature of CoPt-B Nanoparticles Synthesized by Sol-gel Autocombustion Using Sago Starch as a Chelating Agent[J]. Journal of the Korean Ceramic Society, 2020, 57(4): 385-391

[22] Wang YX, Zhang X, Liu Y, et al.. L1₀CoPt-Cu Nanoparticles for High-density Magnetic Recoding by Sol-gel Technique[J]. Journal of Alloys and Compounds, 2014, 582: 511-514

[23] Liu Y, Yang YT, Zhang YJ, et al.. A Facile Route to Synthesis of CoPt Magnetic Nanoparticles[J]. Materials Research Bulletin, 2013, 48(2): 721-724

[24] Zhang YJ, Yang YT, Liu Y, et al.. A Novel Approach to the Synthesis of CoPt Magnetic Nanoparticles[J]. Journal of Physics D-Applied Physics, 2011, 44(29): 295 003

[25] Chen C, Kitakami O, Okamoto S, et al.. Long-range Atomic Ordering and Magnetic Properties of Co_1−xPt_x/SiO₂ Granular Films[J]. Journal of Applied Physics, 2000, 87(96 947-6 949

[26] Csoregh I, Eckstein M. The Crystal and Molecular Structure of 3,3′-(1-naphthylmethylene)bis(4-hydroxycoumarin) ([alpha]-naphthyldicoumarol) in Two Crystal Modifications[J]. Acta Crystallographica Section B, 1979, 35(2): 389-395

[27] Sshdev N, Medwal R, Annapoorni S. Enhanced Phase Stabilization of CoPt in the Presence of Ag[J]. Journal of Applied Physics, 2011, 110(3): 033 901

[28] Wang YX, Zhang XL, Liu Y, et al.. Microstructure and Magnetic Properties of L1₀CoPt Nanoparticles by Ag Addition[J]. Journal of Sol-Gel Science and Technology, 2014, 70(3528-533

[29] Chen T, Fang L, Luo W, et al.. Theoretical Study of Dry Reforming of Methane Catalyzed by Bimetallic Alloy Cluster M₁₂Ni (M=Pt, Sn, Cu) [J]. Chemical Journal of Chinese Universities, 2019, 40(10): 2 135-2 142

RIGHTS & PERMISSIONS

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature