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arXiv · 0911.4077

Spin Transfer Dynamics in Spin Valves with Out-of-plane Magnetized CoNi Free Layers

William H. Rippard·Alina M. Deac·Matthew R. Pufall·Justin M. Shaw·Mark W. Keller·Stephen E. Russek·Gerrit E. W. Bauer·Claudio Serpico
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Abstract

We have measured spin transfer-induced dynamics in magnetic nanocontact devices having a perpendicularly magnetized Co/Ni free layer and an in-plane magnetized CoFe fixed layer. The frequencies and powers of the excitations agree well with the predictions of the single-domain model and indicate that the excited dynamics correspond to precessional orbits with angles ranging from zero to 90 degrees as the applied current is increased at a fixed field. From measurements of the onset current as a function of applied field strength we estimate the magnitude of the spin torque asymmetry parameter lambda ~ 1.5. By combining these with spin torque ferromagnetic resonance measurements, we also estimate the spin wave radiation loss in these devices.

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William H. Rippard, Alina M. Deac, Matthew R. Pufall, Justin M. Shaw, Mark W. Keller, Stephen E. Russek, Gerrit E. W. Bauer, Claudio Serpico. 2009-11-20. Spin Transfer Dynamics in Spin Valves with Out-of-plane Magnetized CoNi Free Layers. https://doi.org/10.1103/physrevb.81.014426

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