- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review Applied

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Hybrid Design for Advanced Magnetic Recording Media: Combining Exchange-Coupled Composite Media with Coupled Granular Continuous Media

P. Chureemart1, R. F. L. Evans2, R. W. Chantrell2, P.-W. Huang3, K. Wang3, G. Ju3, and J. Chureemart1,*

  • 1Computational and Experimental Magnetism Group, Department of Physics, Mahasarakham University, Mahasarakham 44150, Thailand
  • 2Department of Physics, University of York, York YO10 5DD, United Kingdom
  • 3Seagate Technology, Fremont, California 94538, USA

  • *jessada.c@msu.ac.th
PDF

Phys. Rev. Applied 8, 024016 – Published 21 August, 2017

DOI: https://doi.org/10.1103/PhysRevApplied.8.024016

Abstract

In order to enhance the performance of advanced granular recording media and understand the physics behind the mechanism of the reversal process, an atomistic spin-dynamics simulation is used to investigate theoretically the magnetic properties and the magnetization-reversal behavior for a composite media design. This model allows us to investigate the effect of the magnetostatic interaction and inter- and intralayer exchange coupling for a realistic system. The composite granular medium investigated consists of hard and soft composite layers in which the grains are well segregated with a continuous capping layer deposited to provide uniform exchange coupling. We present a detailed calculation aimed to reveal the reversal mechanism. In particular, the angular dependence of the critical field is investigated to understand the switching process. The calculations show a complex reversal mechanism driven by the magnetostatic interaction. It is also demonstrated, at high sweep rates consistent with the recording process, that thermal effects lead to a significant and irreducible contribution to the switching field distribution.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (38)

  1. S. Piramanayagam and K. Srinivasan, Recording media research for future hard disk drives, J. Magn. Magn. Mater. 321, 485 (2009).
  2. J. Chureemart, P. Chureemart, R. Evans, R. W. Chantrell, and K. O’Grady, Magnetic orientation in advanced recording media, J. Phys. D 44, 455002 (2011).
  3. J. Chureemart, L. Lari, T. P. Nolan, and K. O’Grady, The effect of SiO2 content on activation volumes in exchange coupled composite media, J. Appl. Phys. 114, 083907 (2013).
  4. V. Mehta, T. Wang, Y. Ikeda, K. Takano, B. D. Terris, B. Wu, C. Graves, H. A. Durr, A. Scherz, J. Stohr, and O. Hellwig, Extracting magnetic cluster size and its distributions in advanced perpendicular recording media with shrinking grain size using small angle x-ray scattering, Appl. Phys. Lett. 106, 202403 (2015).
  5. C. Papusoi, M. Desai, and R. Acharya, Evaluation of intergranular exchange coupling and magnetic domain size in CoCrPt−SiOx thin films with perpendicular anisotropy, J. Phys. D 48, 215005 (2015).
  6. S. Charap, P.-L. Lu, and Y. He, Thermal stability of recorded information at high densities, IEEE Trans. Magn. 33, 978 (1997).
  7. H. J. Richter, The transition from longitudinal to perpendicular recording, J. Phys. D 40, R149 (2007).
  8. R. Rottmayer, S. Batra, D. Buechel, W. Challener, J. Hohlfeld, Y. Kubota, L. Li, B. Lu, C. Mihalcea, K. Mountfield, K. Pelhos, C. Peng, T. Rausch, M. A. Seigler, D. Weller, and X. Yang, Heat-assisted magnetic recording, IEEE Trans. Magn. 42, 2417 (2006).
  9. D. Weller, O. Mosendz, G. Parker, S. Pisana, and T. S. Santos, L10 FePtX−Y media for heat-assisted magnetic recording, Phys. Status Solidi A 210, 1245 (2013).
  10. S. Granz, K. Barmak, and M. Kryder, Granular L10 FePt:X (X=Ag, B, C, SiOx, TaOx) thin films for heat assisted magnetic recording, Eur. Phys. J. B 86, 81 (2013).
  11. B. D. Terris and T. Thomson, Nanofabricated and self-assembled magnetic structures as data storage media, J. Phys. D 38, R199 (2005).
  12. J. G. Zhu, X. Zhu, and Y. Tang, Microwave assisted magnetic recording, IEEE Trans. Magn. 44, 125 (2008).
  13. R. Victora and X. Shen, Composite media for perpendicular magnetic recording, IEEE Trans. Magn. 41, 537 (2005).
  14. D. Suess, T. Schrefl, S. Fahler, M. Kirschner, G. Hrkac, F. Dorfbauer, and J. Fidler, Exchange spring media for perpendicular recording, Appl. Phys. Lett. 87, 012504 (2005).
  15. Y. Sonobe, D. Weller, Y. Ikeda, M. Schabes, K. Takano, G. Zeltzer, B. Yen, M. E. Best, S. Greaves, H. Muraoka, and Y. Nakamura, Thermal stability and SNR of coupled granular/continuous media, IEEE Trans. Magn. 37, 1667 (2001).
  16. G. Choe, M. Zheng, B. R. Acharya, E. N. Abarra, and J. N. Zhou, Perpendicular recording CoPtCrO composite media with performance enhancement capping layer, IEEE Trans. Magn. 41, 3172 (2005).
  17. J. Yasumori, Y. Sonobe, S. J. Greaves, and K. K. Tham, Approach to high-density recording using CGC structure, IEEE Trans. Magn. 45, 850 (2009).
  18. T. P. Nolan, B. F. Valcu, and H. J. Richter, Effect of composite designs on writability and thermal stability of perpendicular recording media, IEEE Trans. Magn. 47, 63 (2011).
  19. K. K. Tham, S. Saito, D. Hasegawa, N. Itagaki, S. Hinata, S. Ishibashi, and M. Takahashi, Effect of inhomogeneous microstructure of granular layer on inter granular/inter layer exchange coupling in stacked perpendicular recording media, J. Appl. Phys. 112, 093917 (2012).
  20. J. Chureemart, P. Chureemart, J. Pressesky, T. Nolan, and K. O’Grady, Media design and orientation in perpendicular media, IEEE Trans. Magn. 49, 3592 (2013).
  21. C. Morrison, L. Saharan, G. Hrkac, T. Schrefl, Y. Ikeda, K. Takano, J. J. Miles, and T. Thomson, Inter/intra granular exchange and thermal activation in nanoscale granular magnetic materials, Appl. Phys. Lett. 99, 132507 (2011).
  22. L. Saharan, C. Morrison, J. J. Miles, T. Thomson, T. Schrefl, and G. Hrkac, Angle dependence of the switching field of recording media at finite temperatures, J. Appl. Phys. 110, 103906 (2011).
  23. L. Saharan, C. Morrison, Y. Ikeda, K. Takano, J. J. Miles, T. Thomson, T. Schrefl, and G. Hrkac, Grain boundaries in granular materials–A fundamental limit for thermal stability, Appl. Phys. Lett. 102, 142402 (2013).
  24. L. Saharan, C. Morrison, J. J. Miles, T. Thomson, T. Schrefl, and G. Hrkac, Modelling interfacial coupling in thin film magnetic exchange springs at finite temperature, J. Appl. Phys. 114, 153908 (2013).
  25. C. Morrison, L. Saharan, Y. Ikeda, K. Takano, G. Hrkac, and T. Thomson, Quantifying exchange coupling in segregated granular materials, J. Phys. D 46, 475002 (2013).
  26. E. C. Stoner and E. P. Wohlfarth, A mechanism of magnetic hysteresis in heterogeneous alloys, Phil. Trans. R. Soc. Lond. 240, 599 (1948).
  27. R. F. L. Evans, W. J. Fan, P. Chureemart, T. A. Ostler, M. O. A. Ellis, and R. W. Chantrell, Atomistic spin model simulations of magnetic nanomaterials, J. Phys. Condens. Matter 26, 103202 (2014).
  28. W. F. Brown, Thermal fluctuations of a single-domain particle, J. Appl. Phys. 34, 1319 (1963).
  29. E. Boerner, O. Chubykalo-Fesenko, O. Mryasov, R. Chantrell, and O. Heinonen, Moving toward an atomistic reader model, IEEE Trans. Magn. 41, 936 (2005).
  30. P. Chureemart, R. F. L. Evans, and R. W. Chantrell, Dynamics of domain wall driven by spin-transfer torque, Phys. Rev. B 83, 184416 (2011).
  31. S. Saito, S. Hinata, and M. Takahashi, Evaluation of atomic layer stacking structure and Curie temperature of magnetic films for thermally assisted recording media (invited), IEEE Trans. Magn. 50, 102 (2014).
  32. K. K. Tham, S. Hinata, S. Saito, and M. Takahashi, Successful fabrication of high Ku columnar CoPt−SiO2 granular film sputtered under high substrate temperature, J. Appl. Phys. 115, 17B752 (2014).
  33. K. K. Tham, S. Hinata, and S. Saito, Effect of topological bumpy surface underlayer on compositionally modulated atomic layer stacking in high Ku hcp Co80Pt20 film with (00.2) crystallographic texture orientation, IEEE Trans. Magn. 51, 3202404 (2015).
  34. C. Tannous and J. Gieraltowski, The Stoner-Wohlfarth model of ferromagnetism: Static properties, Eur. J. Phys. 29, 475 (2008).
  35. P. Asselin, R. F. L. Evans, J. Barker, R. W. Chantrell, R. Yanes, O. Chubykalo-Fesenko, D. Hinzke, and U. Nowak, Constrained Monte Carlo method and calculation of the temperature dependence of magnetic anisotropy, Phys. Rev. B 82, 054415 (2010).
  36. M. Sharrock and J. McKinney, Kinetic effects in coercivity measurements, IEEE Trans. Magn. 17, 3020 (1981).
  37. M. P. Sharrock, Time dependence of switching fields in magnetic recording media (invited), J. Appl. Phys. 76, 6413 (1994).
  38. O. Hovorka, R. F. L. Evans, R. W. Chantrell, and A. Berger, Rate-dependence of the switching field distribution in nanoscale granular magnetic materials, Appl. Phys. Lett. 97, 062504 (2010).

Outline

Information

Phys. Rev. Applied 8, 024016– Published 21 August, 2017
  • Received 31 January 2017

© 2017 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation