The 81st JSAP Autumn Meeting, 2020

Presentation information

Oral presentation

10 Spintronics and Magnetics » 10.2 Fundamental and exploratory device technologies for spin

[10a-Z08-1~10] 10.2 Fundamental and exploratory device technologies for spin

Thu. Sep 10, 2020 8:45 AM - 11:30 AM Z08

Takeshi Seki(Tohoku Univ.), Tomohiro Taniguchi(AIST)

9:30 AM - 9:45 AM

[10a-Z08-4] Magnetic damping enhancement in L12-ordered Mn3Ir/Fe20Ni80 bilayers

Yuta Kobayashi1, Tetsuya Ikebuchi1, Hiroyuki Iwaki1, Yoichi Shiota1, Ono Teruo1, Takahiro Moriyama1 (1.Kyoto Univ.)

Keywords:chiral, antiferromagnet, ST-FMR

The L12-ordered Mn3Ir is among the Mn3X family (X = Sn, Ge, Ga, Ir, Pt, Rh) which give rise to a large anomalous Hall effect (AHE) due to the Berry phase constituted by the chiral spin structure. In this work, we explore the spin transport properties of the L12-ordered Mn3Ir films and disordered ones by the spin pumping experiments. Since the chiral spin structure is associated with the L12-ordering in this material, one may expect a modification of spin transport properties by the chiral spin structure as it forms the L12-order.
Multilayer of Mn3Ir/Ti/Fe20Ni80/SiO2 were deposited on a MgO (001) substrate by magnetron sputtering with substrate temperatures Ts = 200 and 700℃. Crystal ordering and orientation of the Mn3Ir were characterized by X-ray diffraction. The (001) and (003) superlattice peaks evidence that the L12-ordered Mn3Ir is formed at Ts = 700℃. The crystallinity as well as the chemical order parameter S were characterized. The spin dissipation properties in the Mn3Ir was characterized by the ferromagnetic resonance measurement. In the framework of the spin pumping effect, the spin dissipation property of the Mn3Ir layer can be characterized by looking at the Gilbert damping enhancement of the Fe20Ni80. It is found that the Gilbert damping constant α increases in the sample with Ts = 700℃ comparing with that with Ts = 200℃. This result may suggest that chiral spin structure can increase the spin dissipation. In the presentation, we will discuss the detailed relation between α and S.