[22a-B201-1~11] 10.1 新物質・新機能創成（作製・評価技術）

▼ [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)

キーワード：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.