Yttrium Iron Garnet Thickness Influence on the Spin Pumping in the Bulk Acoustic Wave Resonator

Abstract

The features of phononmagnon interconversion in acoustic resonator determine the efficiency of spin pumping from YIG into Pt that may be detected electrically through the inverse spin Hall effect (ISHE). Based on the methods developed in previous works for calculating resonator structures with a piezoelectric (ZnO) and a magnetoelastic layer in contact with the heavy metal (YIG/Pt), we present the results of numerical calculations of YIG film thickness influence on acoustically driven spin waves. We obtain some YIG film thickness regions with various behavior of dc ISHE voltage UISHE. At micron and submicron thicknesses, the higher spin wave resonance (SWR) modes (both even and odd) can be generated with efficiency comparable and even exceeding that of the main mode. The absolute maximum of UISHE is achieved at the thickness about s1≈208 nm under the excitation of the first SWR.

Theoretical description of power transfer in a magneto-acoustic resonator

“…These devices consist of high overtone bulk acoustic resonators (HBARs) with an additional magnetostrictive layer in which the magnetization dynamics is generated or laminates consisting of piezoelectric and magnetostrictive elements. [13][14][15][16][17][18][19][20][21] Despite these works accurately describe the magnetoelastic coupling near resonance, they do not have simple expressions for the power flow and transducer efficiency or do not include piezoelectric coupling 21 .…”