1. Recent Advances in Nanocontact Spin-Torque Oscillators
- Author
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Johan Åkerman, Ye. Pogoryelov, Sunjae Chung, Ezio Iacocca, Randy K. Dumas, Philipp Dürrenfeld, Pranaba Kishor Muduli, Sohrab R. Sani, and S. Majid Mohseni
- Subjects
Materials science ,Condensed matter physics ,F300 ,Nanomagnet ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Condensed Matter::Materials Science ,Nuclear magnetic resonance ,Stack (abstract data type) ,Electrical and Electronic Engineering ,Electric current ,Anisotropy ,Microwave ,Excitation ,Nanopillar - Abstract
We present a comprehensive review of the most recent advances in nanocontact spin torque oscillators (NC-STOs). NC-STOs are highly tunable, with both applied magnetic field and dc, broadband microwave signal generators. As opposed to the nanopillar geometry, where the lateral cross section of the entire device has been confined to a typically ${ diameter, in NC-STOs, it is only the current injection site that has been laterally confined on top of an extended magnetic film stack. Three distinct material combinations will be discussed: 1) a Co/Cu/NiFe pseudospin valve (PSV) where both the Co and NiFe have a dominant in-plane anisotropy; 2) a Co/Cu/ $[{\rm Co}/{\rm Ni}]_{4}$ orthogonal PSV where the Co/Ni multilayer has a strong perpendicular anisotropy; and 3) a single NiFe layer with asymmetric non-magnetic Cu leads. We explore the rich and diverse magnetodynamic modes that can be generated in these three distinct sample geometries.
- Published
- 2014