Neal Reynolds

Increased low-temperature damping in yttrium iron garnet thin films

We report measurements of the frequency and temperature dependence of ferromagnetic resonance (FMR) for a 15-nm-thick yttrium iron garnet (YIG) film grown by off-axis sputtering. Although the FMR linewidth is narrow at room temperature [corresponding to a damping coefficient

Spin Hall torques generated by rare-earth thin films

\ensuremath{\alpha}=(9.0\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}]

Thickness dependence of spin-orbit torques generated by WTe2

, comparable to previous results for high-quality YIG films of similar thickness, the linewidth increases strongly at low temperatures, by a factor of almost 30. This increase cannot be explained as due to two-magnon scattering from defects at the sample interfaces. We point out that the increased low-temperature linewidth can be explained by impurity relaxation mechanisms that were elucidated 50 years ago in bulk YIG samples. High-purity starting materials and careful optimization of growth protocols to avoid nonstoichiometries should therefore be employed for making low-temperature thin-film YIG devices.

All-optical vector measurement of spin-orbit-induced torques using both polar and quadratic magneto-optic Kerr effects

We report an initial experimental survey of spin-Hall torques generated by the rare-earth metals Gd, Dy, Ho, and Lu, along with comparisons to first-principles calculations of their spin Hall conductivities. Using spin torque ferromagnetic resonance (ST-FMR) measurements and DC-biased ST-FMR, we estimate lower bounds for the spin-Hall torque ratio,

Spin–Orbit Torques in NbSe2/Permalloy Bilayers

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Control of spin-orbit torques through crystal symmetry

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Giant, Temperature-Dependent Spin Hall Torque from Rare-Earth Mixed-Valence YbAl3

\approx

Systematic temperature and thickness dependence of magnetic properties in nanometer-thick garnet films

0.04 for Gd,

Temperature dependence of the spin Hall effect in mixed-valent YbAl

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0.05 for Dy,