Spin pumping is a method for injecting a pure spin current into a non-magnetic metal (NM) by inducing precession
of a neighboring ferromagnet (FM) at its ferromagnetic resonance frequency. A popular method to detect spin
current uses the Inverse Spin Hall Effect (ISHE) to convert the spin current to a detectable charge current and
hence a voltage. In order to better understand the role of time independent and high frequency contributions to
spin pumping, we sought to detect we attempt to detect spin currents by using a second microwave frequency
to detect changes in linewidth of a second ferromagnet due to the spin-torque induced by the spin current from
the first ferromagnet. This dual resonance is achieved by pairing a custom broadband coplanar transmission line
with the high-Q resonant cavity of a commercial electron paramagnetic resonance spectrometer. This technique
is general enough that it should enable the investigation of spin currents in any FM-NM-FM system, for any
orientation of external field, and is not sensitive to voltage artifacts often found in ISHE measurements. We
find that the condition for simultaneous resonance generates a dc spin current that is too small to produce
a measurable change in linewidth of the second ferromagnet, confirming the dominance of ac spin currents in
linewidth enhancement measurements.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.