Skyrmions in magnetic thin films are of intense interest for novel memory devices and neuromorphic computing. One practical route is to design films with perpendicular magnetic anisotropy (PMA) and Dzyaloshinskii-Moriya interaction (DMI). A particular interesting topic in magnetic skyrmions is if/how antiferromagnetic skyrmions ( or antiferromagnetically coupled skyrmions) can be realized. We attempt two approaches to design/fabricate magnetic films which may host antiferromagnetic skyrmions or unusual topological spin textures. |
The first approach is to induce interlayer exchange coupling (IEC) in multilayer with PMA and DMI. We design magneticsuperlattices and systematically study IEC in [Pt/Co/Ru]N and [Pt/Co/Ir]N superlattices that have PMA and large DMI. Although Co layers are separated by Ru(Ir) and Pt that has zero IEC, large oscillatory IEC can still be introduced. Furthermore, we observe unusual hysteresis loop crossing and identify phase diagrams for AFM-IEC and loop crossing.
The second approach is to explore ferrimagnetic films (FeCo)xGd1-x with PMA and possible large DMI as reported. In these materials, the spins of transition metal (FeCo) are antiferromagnetically aligned with the spins of rare earth metal Gd. In addition, (FeCo) and Gd have very different moments and Curie temperatures. The net moment can be tuned by composition and temperature. Near the compensation point, unusual spin textures may be realized (unpublished). |
Relevant publications
1. Interlayer exchange coupling in Pt/Co/Ru and Pt/Co/Ir superlattices, Sabit Karayev, Peyton D. Murray, Durga Khadka, T. R. Thapaliya, Kai Liu, and S. X. Huang, Physical Review Materials (rapid communication), 3, 041401(R) (2019).
2. Dzyaloshinskii–Moriya interaction in Pt/Co/Ir and Pt/Co/Ru multilayer films, Durga Khadka, Sabit Karayev, and S. X. Huang, Journal of Applied Physics, 123, 123905 (2018).
3. Optical and Extreme UV Studies of Spin Dynamics in Metallic and Insulating Ferrimagnets, H. Liu, S. Saha, R. Knut, R. S. Malik, R. Stefanuik, J. Soderstrom, J. Shoup, Durga Khadka, T. R. Thapaliya, S. X. Huang, A. Gupta, O. Karis, D. Karaiskaj, and D.A. Arena, accepted by Journal of Applied Physics, 130, 240901 (2021).
2. Dzyaloshinskii–Moriya interaction in Pt/Co/Ir and Pt/Co/Ru multilayer films, Durga Khadka, Sabit Karayev, and S. X. Huang, Journal of Applied Physics, 123, 123905 (2018).
3. Optical and Extreme UV Studies of Spin Dynamics in Metallic and Insulating Ferrimagnets, H. Liu, S. Saha, R. Knut, R. S. Malik, R. Stefanuik, J. Soderstrom, J. Shoup, Durga Khadka, T. R. Thapaliya, S. X. Huang, A. Gupta, O. Karis, D. Karaiskaj, and D.A. Arena, accepted by Journal of Applied Physics, 130, 240901 (2021).