FMR and thermal spin pumping in garnets|Pt bilayers

A. BUTERA; SANTIAGO J. CARREIRA; MYRIAM AGUIRRE; LARA M. SOLIS; JAVIER E. GÓMEZ

Roma

Otro; 5th Italian School on Magnetism 2020; 2020

The ferrimagnetic insulator Y3Fe5O12 (YIG) is recognized as a model system for studying Spin Hall Effect (SHE) or the inverse effect (ISHE) and Spin Seebeck Effect (SSE) since Pt/YIG 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|Pt microstructures [2]. When a proportion of bismuth (Bi) is added, the magneto-optical properties of YIG increase according to the concentration of bismuth (Bi) at the yttrium site [3]. But there are few studies on how the spin dynamic properties are modified due to this substitution.The aim of this work is to study the generation, propagation and detection of spin waves in thin Y3Fe5O12 (YIG) films in comparison with the material of 5% Bi substitution, i.e. thin films of BiY2Fe5O12 (BYIG). Ferromagnetic resonance (FMR), Inverse spin-Hall effect (ISHE) and spin-Seebeck effect (SSE) measurements were carried out in samples grown on Gd3Ga5O12 (GGG) and Gd3Sc2Ga3O12 (SGGG) substrates by pulsed laser deposition (PLD). Structural characterization was performed by XRD-XRR and HRTEM/STEM-HAADF in samples YIG//GGG, YIG//SGGG and BYIG//SGGG. The combination YIG//SGGG reported to have the best signal of the Inverse spin-Hall effect (VISHE) and Spin Seebeck voltage (VSSE). The out-of-plane angular dependence of the Inverse spin-Hall effect voltage (VISHE) generated by spin pumping showed that VISHE increases initially, with maximum at field-angle of θH ~ 20º, to decrease with increasing angles with minima at field-angle of θH ~ 55º.This work is funded thanks to the SPICOLOST (GA 734187) project framed within ?Horizon 2020 Funding? of the European Union with the MARIE SKŁODOWSKA-CURIE - RISE Actions (Research and Innovation Staff Exchanges) program coordinated by the University of Zaragoza.[1] Rezende, S. M. et al. Physical Review B, 89 (2014) 014416.[2] Du, C. et al. Journal of Applied Physics, 117 (2015) 172603.[3] Kumar, R. et al. Journal of Physics: Condensed Matter, 31 (2019) 435802.