Abstract
We present a comprehensive investigation of propagating spin waves in nanometer-thick yttrium iron garnet (YIG) films. We use broadband spin-wave spectroscopy with integrated coplanar waveguides (CPWs) and antennas on top of continuous and patterned YIG films to characterize spin waves with wave vectors up to 10 rad/μm. All films are grown by pulsed laser deposition. From spin-wave transmission spectra, parameters such as the Gilbert damping constant, spin-wave dispersion relation, group velocity, relaxation time, and decay length are derived, and their dependence on magnetic bias field strength and angle is systematically gauged. For a 40-nm-thick YIG film, we obtain a damping constant of 3.5×10-4 and a maximum decay length of 1.2 mm. We show a strong variation of spin-wave parameters with wave vector, magnetic field strength, and field angle. The properties of spin waves with small wave vectors change considerably with in-plane magnetic bias field up to 30 mT and magnetic field angle beyond 20?. We also compare broadband spin-wave spectroscopy measurements on 35-nm-thick YIG films with integrated CPWs and antennas and demonstrate that both methods provide similar spin-wave parameters.
| Original language | English |
|---|---|
| Article number | 224422 |
| Pages (from-to) | 1-8 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - 26 Dec 2018 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work was supported by the European Research Council (Grants No. ERC-2012-StG 307502-E-CONTROL and No. ERC-PoC-2018 812841-POWERSPIN) and the Academy of Finland (Grants No. 317918 and No. 320021). S.J.H. acknowledges financial support from the Väisälä Foundation. Lithography was performed at the Micronova Nanofabrication Centre, supported by Aalto University. We also acknowledge the computational resources provided by the Aalto Science-IT project.