講演情報
[11a-E214-8]Fast magnetization dynamics and effective damping in Mn4N thin films
〇(M1)Yuma Ando1, Satoshi Iihama1, Koki Nukui4,5, Miki Soma5, Kensuke Hayashi1, Sasaki Yuta2, Shinji Isogami2, Yukiko Takahashi2,3, Shigemi Mizukami5,6, Takahiro Moriyama1 (1.Nagoya Univ., 2.NIMS, 3.RIEC, Tohoku Univ., 4.Tohoku Univ., 5.AIMR, Tohoku Univ., 6.CSIS, Tohoku Univ.)
キーワード：
fast magnetization dynamics、effective damping、TRMOKE
Ferrimagnetic Mn4N thin films have attracted significant attention as promising materials for next-generation spintronic devices due to their low saturation magnetization and robust perpendicular magnetic anisotropy (PMA). In this study, we investigated the laser-induced fast magnetization dynamics and evaluated the effective damping of Mn4N thin films under optical excitation using the time-resolved magneto-optical Kerr effect (TRMOKE) technique. TRMOKE measurements were performed on a 20-nm-thick Mn4N thin film deposited on a single-crystal MgO(001) substrate under various magnetic field application angles. As a result, magnetization precession was observed in the frequency range of 52 to 58 GHz. The experimentally obtained effective damping parameter was 0.07 to 0.08, which is lower than the previously reported values of 0.16 to 0.2 obtained using similar methods. This result suggests that the intrinsic damping constant of Mn4N may be even lower than previously assumed.