Monte Carlo Simulations of the Fast Remagnetization Process in Fept Granular Films

Abstract:

We utilize the Metropolis algorithm to obtain statistical averages of the domain wall length in a FePt granular structure after remagnetization is performed by an ultrashort polarized laser impulse. We propose and check the cluster-size-based order parameter, which along with magnetization, shows the domain wall length, and as a consequence, the average cluster size in the system. We treat the inverse Faraday effect as an external directed magnetic field and show impulse time- and laser power- dependent estimates within the Heisenberg model.

• Periodical: Solid State Phenomena (Volume 312)
• Pages: 281-287
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.312.281
• Online since: November 2020
• Authors: Yuriy Shevchenko*, Roman Volotovskiy, Egor V. Vasiliev, Alexander Perzhu, Dmitrii Kapitan, Alexey Rybin, Konstantin Soldatov, Alexander Makarov, Vladislav Strongin, Alena Medvedeva, Vitalii Kapitan, Konstantin Nefedev
• Keywords: Femtosecond Laser Impulse, Heisenberg Model, Magnetism, Metropolis

References

[1] R. John et al., Magnetisation switching of FePt nanoparticle recording medium by femtosecond laser pulses, Scientific reports 7 (2017) 1­8.

[2] B. Wang, H. Oomiya, A. Arakawa, T. Hasegawa, S. Ishio, Perpendicular magnetic anisotropy and magnetization of L 10 FePt/FeCo bilayer films, Journal of Applied Physics 115(13) (2014) 133908.

DOI: 10.1063/1.4870463

[3] T.J. Klemmer, et al., Structural studies of L10 FePt nanoparticles, Applied Physics Letters 81(12) (2002) 2220­2222.

[4] S. Okamoto, N. Kikuchi, O. Kitakami, T. Miyazaki, Y. Shimada, K. Fukamichi, Chemical­order­ dependent magnetic anisotropy and exchange stiffness constant of FePt (001) epitaxial films, Physical Review B 66(2) (2002) 024413.

DOI: 10.1103/physrevb.66.024413

[5] G.H.O. Daalderop, P.J. Kelly, M.F.H. Schuurmans, Magnetocrystalline anisotropy and orbital moments in transition­metal compounds, Physical Review B, 44(21) (1991) 12054.

DOI: 10.1103/physrevb.44.12054

[6] M.O.A. Ellis, R.W. Chantrell, Switching times of nanoscale FePt: Finite size effects on the linear reversal mechanism, Applied Physics Letters 106(16) (2015) 162407[7] M.O.A. Ellis, E.E. Fullerton, R.W. Chantrell, All­optical switching in granular ferromagnets caused by magnetic circular dichroism, Scientific reports 6 (2016) 30522.

DOI: 10.1063/1.4919051

[8] M. Berritta, R. Mondal, K. Carva, P.M. Oppeneer, Ab initio theory of coherent laser­induced magnetization in metals, Physical review letters 117(13) (2016) 137203.

DOI: 10.1103/physrevlett.117.137203

[9] D. Weller, O. Mosendz, G. Parker, S. Pisana, T.S. Santos, L10 FePtX­Y media for heat­assisted magnetic recording, Physica status solidi (a) 210(7) (2013) 1245­1260.

DOI: 10.1002/pssa.201370040

[10] U. Nowak, R.W. Chantrell, E.C. Kennedy, Monte Carlo simulation with time step quantification in terms of Langevin dynamics, Physical review letters, 84(1) (2000) 163.

DOI: 10.1103/physrevlett.84.163

[11] X.Z. Cheng, M.B.A. Jalil, H.K. Lee, Y. Okabe, Mapping the Monte Carlo scheme to Langevin dynamics: a Fokker­Planck approach, Physical review letters 96(6) (2006) 067208.

DOI: 10.1103/physrevlett.96.067208