[22a-B201-1~11] 10.1 Emerging materials in spintronics and magnetics (including fabrication and characterization methodologies)

▼ [22a-B201-10] Revealing the local magnetic properties of cubic ferrimagnetic full-Heusler alloys using synchrotron Mössbauer spectroscopy

〇(P)Phillip David Bentley¹, Songtian Li¹, Tengyu Guo², Guoqiang Yu^2,3, Takaya Mitsui⁴, Yasuhiro Kobayashi⁵, Kosuke Fujiwara⁴, Seiji Sakai¹ (1.QST Takasaki, 2.Songshan Lake Mater., 3.Beijing Nat. Lab., 4.QST Sayo, 5.IIRNS Kyoto Kumatori)

Keywords:Spintronics, Ferrimagnetism, Perpendicular Magnetic Anisotropy

In this study we have analysed ferrimagnetic cubic full-Heusler Mn2FexGa (MFG)/Cr/MgO(001) heterostructures with different Fe concentrations (x) using a variety of techniques including reflection high-energy electron diffraction, X-ray diffraction, SQUID and synchrotron Mössbauer spectroscopy [1]. As discussed previously, MFG shows several properties suitable for spintronic applications including a large PMA, a small associated total magnetic moment, and a theoretically predicted high spin polarization [2]. What we find by using Mössbauer spectroscopy is that the local moment of Fe is very similar to its expected value [2]. These results suggest that a Mn 4a – Fe 4b (L21B) and Mn 4c – Ga 4d (B2) disorder is favoured over a Mn 4c – Fe 4b (DO3) and Mn 4a – Ga 4d (A2) disorder and therefore there is only a minor decrease in spin polarization in cubic MFG [3]. In addition to its large PMA, the absence of unfavourable antisite defects and possibility of it being highly spin polarized further demonstrate MFG’s potential in applications such as MRAM.
[1] T. Mitsui et al., Phys. Rev. Lett., 2020, 125, 236806; [2] A. Kundu et al., Intermetallics, 2018, 93, 209-216; [3] S. Kurdi et al., J. Phys. D: Appl. Phys, 2022, 55, 185305.