Tailoring magnetic properties through inter-atomic engineering

Spin-Ion Technologies is a spin-off company from the University of Paris-Saclay and CNRS in Palaiseau, France. For more than 20 years the research team has been developing a patented process solution to treat magnetic materials for the purpose of enhancing their performances, reducing manufacturing costs and for improving yield for both HDD and MRAM applications. Spin-Ion Technologies, provides a revolutionary process solution based on post-growth He+ ion irradiation to tailor the magnetic properties of thin magnetic films at the atomic scale and improve their performances. The utilization of light ions provides the precise control of inter-atomic displacements through the low energy transfer.1


The key feature of the technology is the precise control of magnetic properties1-9  including - perpendicular magnetic anisotropy, ferromagnetic order, damping, Dzyaloshinskii-Moriya Interaction, domain wall/skyrmions dynamics or SOT switching - through inter-atomic engineering via:

  • The control of interface inter-mixing in magnetic multilayers (Co/Pt, Co/Ni, Co/Pd, CoFeB-MgO…)
  • The enhancement of chemical order (FePt, FePd…) and crystallization (CoFeB-MgO...) process at lower temperatures than pure annealing
  • The fabrication of planar magnetic nanostructures by using ion irradiation through a mask

Control of perpendicular anisotropy in Co/Pd multilayers as a function of the He+ fluence

Kerr microscopy image showing domain wall pinning due to contrast of anisotropy after irradiation through a mask in CoFeB-MgO materials

The technology has been tested by leading laboratories and companies involved in spintronics including:
  • University of California San Diego (USA)
  • University of California Davies (USA)
  • Georgetown University (USA)
  • Northwestern university (USA)
  • University of Lorraine (France)
  • University of Cambridge (UK)
  • University of Beihang (China)
  • Spintec Grenoble (France)
  • University of Gothenburg (Sweden)
  • Western Digital (USA)
  • Singulus Technologies (Germany)

1Tailoring magnetism by light-ion irradiation, J Fassbender, D Ravelosona, Y Samson, Journal of Physics D: Applied Physics 37 (2004)

2Ordering intermetallic alloys by ion irradiation: A way to tailor magnetic media, H Bernas & D Ravelosona, Physical review letters 91, 077203 (2003)

3Influence of ion irradiation on switching field and switching field distribution in arrays of Co/Pd-based bit pattern media, T Hauet & D Ravelosona, Applied Physics Letters 98, 172506 (2011)

4Irradiation-induced tailoring of the magnetism of CoFeB/MgO ultrathin films, T Devolder & D Ravelosona, Journal of Applied Physics 113, 203912 (2013)

5Enhancing domain wall velocity through interface intermixing in W-CoFeB-MgO films with perpendicular anisotropy, X Zhao & W.Zhao & D Ravelosona, Applied Physics Letter 115, 122404 (2019)

6Suppression of all-optical switching in He+  irradiated Co/Pt multilayers: influence of the domain-wall energy, M El Hadri & S Mangin & D Ravelosona,  J. Phys. D: Appl. Phys. 51, 215004 (2018)

7Enhancement of the Dzyaloshinskii-Moriya Interaction and domain wall velocity through interface intermixing in Ta/CoFeB/MgO, L Herrera Diez & D Ravelosona, Physical Review B 99, 054431 (2019)

8Controlling magnetism by interface engineering, L Herrera Diez & D Ravelosona, Book Magnetic Nano- and Microwires 2nd Edition, Elsevier (2020)

9Reduced spin torque nano-oscillator linewidth using He+ irradiation, S Jiang & D Ravelosona & J  Akerman, Appl. Phys. Lett. 116, 072403 (2020)