Skip to main content
SpringerLink
Log in

Annealing effects and perpendicular magnetic properties of sputtered Co2FeSi alloy films

  • Published:
Applied Physics A Aims and scope Submit manuscript

Abstract

A series of Co2FeSi (CFS) films sandwiched by MgO and Pt layers are sputtered. For the as-deposited films, the magnetic easy axis lies in the sample plane. After annealing, perpendicular magnetic anisotropy (PMA) is shown to build in the stacks with CFS thickness ranged from 2.5 to 3.8 nm and is determined to be the order of 105–106 erg/cm3 in magnitude. The largest saturation magnetization of 1009 ± 41 emu/cm3, close to the bulk value of CFS, is obtained in the annealed stacks. The thickness of a magnetic dead layer is shown to monotonically increase with annealing temperature. This can be ascribed to the progress of the oxidation from the CFS/MgO interface with annealing temperature. No PMA is observed without Pt buffer or MgO top layers. The positive contributions to the PMA made by the Pt/CFS and CFS/MgO interfaces are experimentally verified. The strong PMA is shown to be maintained in the stacks with 4 nm Pt buffer and 0.5 nm MgO layers after high-temperature annealing. Our results provide some useful information on the design for the next generation of CFS-based spintronic devices.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. X. Li, S.J. Lin, M. Dc, Y.C. Liao, C.Y. Yao, A. Naeemi, W. Tsai, S.X. Wang, materials requirements of high-speed and low-power spin-orbit-torque magnetic random-access memory. IEEE J. Electron Devices Soc. 8, 674–680 (2020)

    Article  Google Scholar 

  2. P.C. Filippou, J. Jeong, Y. Ferrante, S.H. Yang, T. Topuria, M.G. Samant, S.S.P. Parkin, Chiral domain wall motion in unit-cell thick perpendicularly magnetized Heusler films prepared by chemical templating. Nat. Commun. 9, 4653 (2018)

    Article  ADS  Google Scholar 

  3. S. Ikegawa, F.B. Mancoff, J. Janesky, S. Aggarwal, Magnetoresistive random access memory: present and future. IEEE Trans. Electron Devices 67(4), 1407–1419 (2020)

    Article  ADS  Google Scholar 

  4. S. Ikeda, K. Miura, H. Yamamoto, K. Mizunuma, H.D. Gan, M. Endo, S. Kanai, J. Hayakawa, F. Matsukura, H. Ohno, A perpendicular-anisotropy CoFeB–MgO magnetic tunnel junction. Nat. Mater. 9, 721–724 (2010)

    Article  ADS  Google Scholar 

  5. Y.P. Kabanov, R.D. Shull, C. Zheng, P.W.T. Pong, D.B. Gopman, Asymmetric magnetization reversal of the Heusler alloy Co2FeSi as free layer in an CoFeB/MgO/Co2FeSi magnetic tunnel junction. Appl. Surf. Sci. 536, 147672 (2021)

    Article  Google Scholar 

  6. S. Wurmehl, G.H. Fecher, H.C. Kandpal, V. Ksenofontov, C. Felser, H.J. Lin, Investigation of Co2FeSi: the Heusler compound with highest Curie temperature and magnetic moment. Appl. Phys. Lett. 88(3), 032503 (2006)

  7. C. Sterwerf, S. Paul, B. Khodadadi, M. Meinert, J.M. Schmalhorst, M. Buchmeier, C.K. A. Mewes, T. Mewes, G. Reiss, Low Gilbert damping in Co2FeSi and Fe2CoSi films. J. Appl. Phys. 120(8), 083904 (2016)

  8. T. Usami, S. Fujii, S. Yamada, Y. Shiratsuchi, R. Nakatani, K. Hamaya, Giant magnetoelectric effect in an L21-ordered Co2FeSi/Pb(Mg1/3Nb2/3)O3-PbTiO3 multiferroic heterostructure. Appl. Phys. Lett. 118, 142402 (2021)

  9. G. Hoffmann, B. Jenichen, J. Herfort, Epitaxial growth of Co2FeSi/MgO/GaAs(001) heterostructures using molecular beam epitaxy. J. Cryst. Growth 512, 194–197 (2019)

    Article  ADS  Google Scholar 

  10. S. T. Li, Y. Sakuraba, T. Sasaki, J.M. Chen, S. Bosu, K. Hono, Enhanced current-perpendicular-to-plane giant magnetoresistance by improvement of atomic order of Co2FeSi Heusler alloy film through Ag doping. AIP Adv. 8, 075230 (2018)

  11. C.L. Wang, S.H. Zhang, S.D. Li, H.L. Du, G.X. Zhao, D.R. Cao, Improvement of high-frequency properties of Co2FeSi Heusler films by ultrathin Ru underlayer. Chinese Phys. B 29, 046202 (2020)

  12. K. Wang, Y.H. Wang, J. Ma, Z. Xu, Sputtering fabrication of GdFeCo alloy films with perpendicular magnetic anisotropy. Vacuum 163, 75–80 (2019)

    Article  ADS  Google Scholar 

  13. K. Shinohara, T. Suzuki, Y. Takamura, S. Nakagawa, Methods to induce perpendicular magnetic anisotropy in full-Heusler Co2FeSi thin layers in a magnetic tunnel junction structure. AIP Adv. 8, 055923 (2018)

  14. F. William, H. Atsufumi, Heusler alloys with BCC tungsten seed layers for GMR junctions. J. Magn. Magn. Mater. 453, 182–185 (2018)

    Article  Google Scholar 

  15. K. Takahide, K. Tomonari, K. Jinhyeok, T. Arata, T. Shigeki, S. Yoshiaki, T. Koki, Interface magnetic anisotropy of Pd/Co2FexMn1-xSi/MgO layered structures. Mater. Trans. 57(6), 773–776 (2016)

    Article  Google Scholar 

  16. A. Conca, A. Niesen, G. Reiss, B. Hillebrands, Evolution of the interfacial perpendicular magnetic anisotropy constant of the Co2FeAl/MgO interface upon annealing. J. Phys. D-Appl. Phys. 51(16), 165303 (2018)

  17. M.S. Gabor, M. Nasui, A. Timar-Gabor, Perpendicular magnetic anisotropy in Pt/Co-based full Heusler alloy/MgO thin-film structures. Phys. Rev. B 100, 144438 (2019)

  18. C. Grezes, X. Li, K.L. Wong, F. Ebrahimi, P.K. Amiri, K.L. Wang, Voltage-controlled magnetic tunnel junctions with synthetic ferromagnet free layer sandwiched by asymmetric double MgO barriers. J. Phys. D-Appl. Phys. 53(1), 014006 (2020)

  19. K. Wang, Y.M. Tang, X.P. Xiao, Effects of Pd- and Ta-buffer layer on magnetic and interfacial perpendicular properties of sputtered Co2FeSi/MgO heterostructures. Surf. Eng. 37(4), 497–504 (2021)

    Article  Google Scholar 

  20. N. Patra, C.L. Prajapat, P.D. Babu, S. Rai, S. Kumar, S.N. Jha, D. Bhattacharyya, Pulsed laser deposited Co2FeSi Heusler alloy thin films: effect of different thermal growth processes. J. Alloys Compd. 804, 470–485 (2019)

    Article  Google Scholar 

  21. X.Q. Li, Y. Wu, S. Gao, X.G. Xu, J. Miao, Y. Jiang, Perpendicular magnetic anisotropy in Co2FeAl0.5Si0.5/MgO bottom electrodes for magnetic tunnel junctions. Thin Solid Films. 545, 503–508 (2013)

  22. Y. Takamura, Y. Stutler, E. Matsushita, K. Shinohara, T. Suzuki, S. Nakagawa, Perpendicular magnetic anisotropy in full-Heusler Co2FeSi alloy and MgO bilayers. J. Magn. Soc. Jpn. 43, 120–124 (2019)

    Article  Google Scholar 

  23. J.H. Jung, S.H. Lim, S. R. Lee, Strong perpendicular magnetic anisotropy in thick CoFeB films sandwiched by Pd and MgO layers. Appl. Phys. Lett. 96(4), 042503 (2010)

  24. A. Basha, H.R. Fu, G. Levi, G. Leitus, A. Kovács, C.Y. You, A. Kohn, Interface alloying of ultra-thin sputter-deposited Co2MnSi films as a source of perpendicular magnetic anisotropy, J. Magn. Magn. Mater. 489, 165367 (2019).

  25. T. Huang, X.M. Cheng,· X.W. Guan, S. Wang, X.S. Miao, Perpendicular magnetization of Co2FeAl full-Heusler alloy films induced by Pt insertion. J Mater Sci: Mater Electron. 28, 9606–9611 (2017)

  26. Z.H. Wen, H. Sukegawa, S. Mitani, K. Inomata, Perpendicular magnetization of Co2FeAl full-Heusler alloy films induced by MgO interface. Appl. Phys. Lett. 98, 242507 (2011)

  27. C.Y. You, H.R. Fu, X. Zhang, N. Tian, P.W. Wang, Interaction of Ta–O and perpendicular magnetic anisotropy of Ta/Pd(0–2.4nm)/Co2FeAl0.5Si0.5/MgO/Ta structured films. J. Magn. Magn. Mater. 377, 276–280 (2015)

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 51961004) and the Key Research & Development Plan of Jiangxi Province (Grant No. 20192BBEL50018).

Author information

Authors and Affiliations

  1. School of Mechanical and Electronic Engineering, East China University of Technology, Nanchang, 330013, China

    Ke Wang, Xiaopeng Xiao, ZiKun Xu, Liang Wu & Jian Liu

Authors
  1. Ke Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Xiaopeng Xiao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. ZiKun Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Liang Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Jian Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Ke Wang.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, K., Xiao, X., Xu, Z. et al. Annealing effects and perpendicular magnetic properties of sputtered Co2FeSi alloy films. Appl. Phys. A 127, 725 (2021). https://doi.org/10.1007/s00339-021-04866-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00339-021-04866-2

Keywords

Search

Navigation