[22p-A205-1~18] 10.2 Fundamental and exploratory device technologies for spin

▲ [22p-A205-1] Magnetoacoustic resonance in RE-TM ferrimagnets

〇Hiroki Matsumoto¹, Kay Yakushiji², Takuya Kawada¹, Masashi Kawaguchi¹, Masamitsu Hayashi¹ (1.The Univ. of Tokyo, 2.AIST)

Keywords:surface acoustic wave, ferrimagnet, magnetoacoustic resonance

Surface acoustic waves (SAW) on a piezoelectric substrate can drive spin wave resonance (SWR) in a ferromagnetic thin film owing to magnetoelastic coupling. This SAW-magnon coupling induces many interesting phenomena such as acoustic spin pumping and nonreciprocal SAW propagation. In addition, SAW-driven magnetization switching in ferromagnets has been demonstrated using resonant and non-resonant coupling. In conventional transition-metal ferromagnets such as CoFeB and NiFe that are widely utilized in spintronic devices, resonance frequency is typically larger than 5 GHz, which makes an efficient SAW-magnon coupling difficult because of the relatively low SAW frequency (often a few GHz or lower). As an alternative to them, we focus on rare-earth transition metal (RE-TM) ferrimagnets. RE-TM ferrimagnetic alloys such as GdFeCo and TbCo have been gaining growing attention because of its tunable magnetization and angular momentum. By changing the composition, magnetic resonance frequency in the RE-TM ferrimagnet is also controllable. Therefore, the RE-TM ferrimagnet is a good candidate to realize an efficient magnetization switching by SAW. In this work, we study acoustically driven SWR in a RE-TM ferrimagnet GdCo.