[21a-P02-1~50] 10 Spintronics and Magnetics(Poster)

▲ [21a-P02-42] Magneto-optical Kerr effect of a L1₂-ordered Mn₃Ir film

〇Kihiro Yamada¹, Kotarou Yamaguchi¹, Yuta Kobayashi², Teruo Ono², Takahiro Moriyama², Takuya Satoh¹ (1.Tokyo Tech, 2.ICR, Kyoto Univ.)

Keywords:antiferromagnet, Magneto-optical Kerr effect

Non-collinear chiral antiferromagnet Mn₃Ir [1] films show a sizable anomalous Hall effect owing to the topological spin textures with the assistance of the spin-orbit coupling which breaks the time-mirror symmetry. The magneto-optical Kerr effects (MOKE) sharing the same microscopic origin as the anomalous Hall effect should be substantial in the Mn₃Ir films [1] but have not been experimentally observed yet.
Here, we show the MOKE of a 20-nm-thick L1₂-ordered Mn₃Ir film on MgO (001). The film was grown at 600℃ by dc magnetron sputtering. The films were capped by a 5-nm-thick SiO₂ for preventing oxidization. With the scanning MOKE microscope, we observed a maze magnetic domain structure of the Mn₃Ir film, which responds to a magnetic field of ±9 T. The evaluated MOKE is recorded large among chiral antiferromagnets and comparable to ferromagnetic metals.

[1] H. Iwaki et al., Appl. Phys. Lett. 116, 022408 (2020).