Unconventional Spin Pumping and Magnetic Damping in an Insulating Compensated Ferrimagnet

Yan Li (1) , Dongxing Zheng (1) , Bin Fang (1) , Chen Liu (1) , Chenhui Zhang (1) , Aitian Chen (1) , Yinchang Ma (1) , Ka Shen (2) , Haoliang Liu (3) , Aurelien Manchon (4) , Xixiang Zhang (1)

1 KAUST - King Abdullah University of Science and Technology [Saudi Arabia]
2 BNU - Beijing Normal University
3 HIT - Harbin Institute of Technology
4 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

Recently, the interest in spin pumping has escalated from ferromagnets into antiferromagnetic systems, potentially enabling fundamental physics and magnonic applications. Compensated ferrimagnets are considered alternative platforms for bridging ferroand antiferromagnets, but their spin pumping and the associated magnetic damping have been largely overlooked so far despite their seminal importance for magnonics. Herein, we report an unconventional spin pumping together with magnetic damping in an insulating compensated ferrimagnet Gd3Fe5O12. Remarkably, we unambiguously identified the divergence of the nonlocal effective magnetic damping induced by spin pumping close to the compensation temperature in Gd3Fe5O12/Cu/Pt heterostructures. Furthermore, the coherent and incoherent spin currents, generated by spin pumping and spin Seebeck effect respectively, undergo a distinct direction change with the variation of temperature. The physical mechanisms underlying these observations are self-consistently clarified by the ferrimagnetic counterpart of spin pumping and the handedness-related spin-wave spectra. Our findings broaden the conventional paradigm of the ferromagnetic spin pumping model and open new opportunities for exploring the ferrimagnetic magnonic devices.

Mots clés: spin pumping; magnetic damping; coherent and incoherent spin currents; handedness; insulating compensated ferrimagnet

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Yan Li, Dongxing Zheng, Bin Fang, Chen Liu, Chenhui Zhang, et al.. Unconventional Spin Pumping and Magnetic Damping in an Insulating Compensated Ferrimagnet. Advanced Materials, 2022, 34 (24), pp.2200019. ⟨10.1002/adma.202200019⟩. ⟨hal-03831734⟩