Frequency and magnetic field mapping of magnetoelastic spin pumping in high overtone bulk acoustic wave resonator

I. I. Pyataikin,V. A. Kotov,V. A. Luzanov,A. O. Raevskiy,N. I. Polzikova,S. G. Alekseev

doi:10.1063/1.5007685

I. I. Pyataikin, V. A. Kotov + Show 4 more

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https://doi.org/10.1063/1.5007685

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Abstract

We report on the first observation of microvolt-scale inverse spin Hall effect (ISHE) dc voltage driven by an acoustic spin pumping (ASP) in a bulk acoustic wave (BAW) resonator formed by a Al-ZnO-Al-YIG(1)-GGG-YIG(2)-Pt structure. When 2 mW power is applied to an Al-ZnO-Al transducer, the voltage VISHE ∼ 4 μV in the Pt film is observed as a result of resonant ASP from YIG(2) to Pt in the area ∼ 170 μm. The results of frequency and magnetic field mapping of VISHE(f,H) together with reflectivity of the resonator show an obvious agreement between the positions of the voltage maxima and BAW resonance frequencies fn(H) on the (f, H) plane. At the same time a significant asymmetry of the VISHE(fn(H)) value in reference to the magnetoelastic resonance (MER) line fMER(H) position is revealed, which is explained by asymmetry of the magnetoelastic waves dispersion law.

Highlights

Frequency and magnetic field mapping of magnetoelastic spin pumping in high overtone bulk acoustic wave resonator
The generation of pure spin current from yttrium iron garnet (YIG) to Pt detected by inverse spin Hall effect (ISHE) under magnetic dynamics excitation in a composite magnetoelectric high overtone bulk acoustic wave resonator (HBAR)[16,17,18,19,20] was demonstrated for the first time.[21]
In this paper we report on the observation of considerably larger HBAR-driven ISHE voltage

Summary

Introduction

Interest in the magnetoelastic (ME) coupling between spin waves (SW) and acoustic waves (AW) in ferromagnets renewed recently in the fields of microwave electronics, magnonics, and spintronics.[1,2,3,4,5,6,7,8,9,10,11] In particular, much attention is given to acoustically driven (AD) excitation of magnetic oscillations in artificial multiferroic structures due to strain mediated coupling between the microwave electric field in a piezoelectric layer and magnetization in a ferromagnetic layer.[6,7,8,9,10,11]In the field of microwave spintronics, acoustic spin pumping (ASP) is the generation of spinpolarized electron currents in normal metal from AD magnetization precession in an attached magnetic material.[12,13,14] In ferrimagnetic insulator yttrium iron garnet (YIG)/paramagnetic metal (platinum, Pt) bilayers, a pure spin current generation not accompanied by charge current was discovered and investigated in numerous works.[15]. Frequency and magnetic field mapping of magnetoelastic spin pumping in high overtone bulk acoustic wave resonator

Results

Conclusion