Tuning of the Dzyaloshinskii-Moriya interaction by He+ion irradiation

• Main Authors: Fassbender, J. (Author), Jué, E. (Author), Nembach, H.T (Author), Poetzger, K. (Author), Shaw, J.M (Author), Silva, T.J (Author)
• Format: Article
• Language: English
• Published: American Institute of Physics Inc. 2022
• Subjects: Boron compounds; Cobalt compounds; Dzyaloshinskii-Moriya interaction; Exchange mechanism; Fluence dependence; Fluences; Intelligent systems; Ion bombardment; Ions; Ions irradiation; Iron compounds; Monte Carlo methods; Platinum; Site exchange
• Online Access: View Fulltext in Publisher
• ISBN: 00218979 (ISSN)
• DOI: 10.1063/5.0080523

We studied the impact of He+ irradiation on the Dzyaloshinskii-Moriya interaction (DMI) in Ta/Co20Fe60B20/Pt/MgO samples. We found that irradiation of 40 keV He+ ions increases the DMI by approximately 20% for fluences up to 2 × 1016 ions/cm2 before it decreases for higher fluence values. In contrast, the interfacial anisotropy shows a distinctly different fluence dependence. To better understand the impact of the ion irradiation on the Ta and Pt interfaces with the Co20Fe60B20 layer, we carried out Monte-Carlo simulations, which showed an expected increase in disorder at the interfaces. A moderate increase in disorder increases the total number of triplets for the three-site exchange mechanism and consequently increases the DMI. Our results demonstrate the significance of disorder for the total DMI. © 2022 Author(s).