FMR and thermal spin pumping enhanced by substrate strains in YIG/Pt and YIG/Ta bilayers

LARA M. SOLIS; SANTIAGO J. CARREIRA; JAVIER E. GÓMEZ; BRIATICO, J; A. ANANE; A. BUTERA; L. B. STEREN; MYRIAM AGUIRRE

Bariloche

Workshop; International workshop on Spintronics 2022; 2022

Centro Atómico Bariloche

The ferrimagnetic insulator Y3Fe5O12(YIG) is recognized as a model system for spintronic and magnonic phenomena including spin pumping, spin Seebeck, proximity effects and spin wave propagation. In these materials, the spin current occurs via spin-waves or magnons. Magnons can be excited and detected electrically via the spin Hall effect (SHE) and the anomalous spin Hall effect (ASHE) and excited thermally via the spin Seebeck effect (SSE). To detect the spin current, a thin non-magnetic layer, such as Pt or Ta, is deposited on top of the material of interest. This converts the spin current into an observable thermoelectric voltage (VSSE) by way of the Inverse Spin Hall Effect (ISHE). YIG/Pt and YIG/Ta systems enable the efficient spin-charge conversion and pure detection of spin-current effects, respectively, because their unique spin dynamic and magneto-optical properties [1]. These properties allow clean detection of the pure spin current thanks to spin-orbit effects in YIG/metal bilayers [2].Samples with different thicknesses of pure YIG films on Gd3Ga5O12 (111) (GGG) and substituted (SGGG) substrates were grown by pulsed laser deposition (PLD). General Phase Analysis (GPA) shows that the films deposited on SGGG are lattice matched to the substrate with low compressive strain while those grown on GGG substrates are subject to tensile strains. Through ferromagnetic resonance measurements, we find that all the YIG films have low Gilbert damping constant, but the resonance field reveals an enhanced perpendicular anisotropy associated with compressive strain in YIG/SGGG samples. Moreover, the transport behavior of metal/YIG/SGGG films shows an increase of spin mixing conductance as compared with metal/YIG/GGG films. In addition, measurements of the Spin Seebeck Effect confirmed what it was found in the results of spin pumping.This work is funded thanks to the SPICOLOST (GA 734187) project framed within “Horizon 2020 Funding” of the European Union with the MARIE SKLODOWSKA - CURIE - RISE Actions program coordinated by the University of Zaragoza and ANPCYT Grant PICT 2019-02781.References[1] S. M. Rezende, R. L. Rodríguez-Suárez, R. O. Cunha, A. R. Rodrigues, F. L. A. Machado, G. F. Guerra, and A. Azevedo, Physical Review B 89, 014416(2014).[2] C. Du, H. Wang, P. Hammel, and F. Yang, Journal of Applied Physics 117, 172603(2015).