Skip to main content
Log in

In situ electron holography of the dynamic magnetic field emanating from a hard-disk drive writer

  • Research Article
  • Published:
Nano Research Aims and scope Submit manuscript

Abstract

The proliferation of mobile devices in society accessing data via the “cloud” is imposing a dramatic increase in the amount of information to be stored on hard disk drives (HDD) used in servers. Forecasts are that areal densities will need to increase by as much as 35% compound per annum and by 2,020 cloud storage capacity will be around 7 zettabytes corresponding to areal densities of 2 Tb/in2. This requires increased performance from the magnetic pole of the electromagnetic writer in the read/write head in the HDD. Current state-of-art writing is undertaken by morphologically complex magnetic pole of sub 100 nm dimensions, in an environment of engineered magnetic shields and it needs to deliver strong directional magnetic field to areas on the recording media around 50 nm × 13 nm. This points to the need for a method to perform direct quantitative measurements of the magnetic field generated by the write pole at the nanometer scale. Here we report on the complete in situ quantitative mapping of the magnetic field generated by a functioning write pole in operation using electron holography. The results point the way towards a new nanoscale magnetic field source to further develop in situ transmission electron microscopy.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Richter, H. J. The transition from longitudinal to perpendicular recording. J. Phys. D. Appl. Phys. 2007, 40, R149–R177.

    Article  Google Scholar 

  2. Manalis, S.; Babcock, K.; Massie, J.; Elings, V.; Dugas, M. Submicron studies of recording media using thin film magnetic scanning probes. Appl. Phys. Lett. 1995, 66, 2585–2587.

    Article  Google Scholar 

  3. Stipe, B. C.; Strand, T. C.; Poon, C. C.; Balamane, H.; Boone, T. D.; Katine, J. A.; Li, J. L.; Rawat, V.; Nemoto, H.; Hirotsune, A. et al. Magnetic recording at 1.5 Pb m−2 using an integrated plasmonic antenna. Nat. Photonics 2010, 4, 484–488.

    Article  Google Scholar 

  4. Challener, W. A.; Peng, C. B.; Itagi, A. V.; Karns, D.; Peng, W.; Peng, Y. G.; Yang, X. M.; Zhu, X. B.; Gokemeijer, N. J.; Hsia, Y. T. et al. Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer. Nat. Photonics 2009, 3, 220–224.

    Article  Google Scholar 

  5. Thomas, J. M.; Simpson, E. T.; Kasama, T.; Dunin-Borkowski, R. E. Electron holography for the study of magnetic nanomaterials. Acc. Chem. Res. 2008, 41, 665–674.

    Article  Google Scholar 

  6. Masseboeuf, A.; Marty, A.; Bayle-Guillemaud, P.; Gatel, C.; Snoeck, E. Quantitative observation of magnetic flux distribution in new magnetic films for future high density recording media. Nano Lett. 2009, 9, 2803–2806.

    Article  Google Scholar 

  7. Kim, J. J.; Hirata, K.; Ishida, Y.; Shindo, D.; Takahashi, M.; Tonomura, A. Magnetic domain observation in writer pole tip for perpendicular recording head by electron holography. Appl. Phys. Lett. 2008, 92, 162501.

    Article  Google Scholar 

  8. Hirata, K.; Ishida, Y.; Akashi, T.; Shindo, D.; Tonomura, A. Electron holography study of magnetization behavior in the writer pole of a perpendicular magnetic recording head by a 1 MV transmission electron microscope. J. Electron Microsc. 2012, 61, 305–308.

    Article  Google Scholar 

  9. Goto, T.; Jeong, J. S.; Xia, W. X.; Akase, Z.; Shindo, D.; Hirata, K. et al. Electron holography of magnetic field generated by a magnetic recording head. Microscopy 2013, 62, 383–389.

    Article  Google Scholar 

  10. Ehrenberg, W.; Siday, R. E. The refractive index in electron optics and the principles of dynamics. Proc. Phys. Soc. Sect. B 1949, 62, 8–21.

    Article  Google Scholar 

  11. Aharonov, Y.; Bohm, D. Significance of electromagnetic potentials in the quantum theory. Phys. Rev. 1959, 115, 485–491.

    Article  Google Scholar 

  12. Aharonov, Y.; Bohm, D. Further considerations on electromagnetic potentials in the quantum theory. Phys. Rev. 1961, 123, 1511–1524.

    Article  Google Scholar 

  13. Tonomura, A.; Matsuda, T.; Suzuki, R.; Fukuhara, A.; Osakabe, N.; Umezaki, H.; Endo, J.; Shingawa, K.; Sugita, Y.; Fujiwara, H. Observation of Aharonov-Bohm effect by electron holography. Phys. Rev. Lett. 1982, 48, 1443–1446.

    Article  Google Scholar 

  14. Snoeck, E.; Gatel, C. Magnetic Mapping Using Electron Holography in Transmission Electron Microscopy in Micro-nanoelectronics; Claverie, A., Eds; ISTE Ltd. and John Wiley & Sons Inc.: London, 2012.

  15. Scholz, W.; Fidler, J.; Schrefl, T.; Suess, D.; Dittrich, R.; Forster, H.; Tsiantos, V. Scalable parallel micromagnetic solvers for magnetic nanostructures. Comput. Mater. Sci. 2003, 28, 366–383.

    Article  Google Scholar 

  16. Ladak, S.; Read, D. E.; Perkins, G. K.; Cohen, L. F.; Branford, W. R. Direct observation of magnetic monopole defects in an artificial spin-ice system. Nat. Phys. 2010, 6, 359–363.

    Article  Google Scholar 

  17. Zhang, S.; Gilbert, I.; Nisoli, C.; Chern, G. W.; Erickson, M. J.; O’Brien, L.; Leighton, C.; Lammert, P. E.; Crespi, V. H.; Schiffer, P. Crystallites of magnetic charges in artificial spin ice. Nature 2013, 500, 553–557.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Christophe Gatel.

Electronic supplementary material

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Einsle, J.F., Gatel, C., Masseboeuf, A. et al. In situ electron holography of the dynamic magnetic field emanating from a hard-disk drive writer. Nano Res. 8, 1241–1249 (2015). https://doi.org/10.1007/s12274-014-0610-0

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12274-014-0610-0

Keywords

Navigation