We study the current and temperature dependences of the microwave voltage emission of spin-valve nanopillars subjected to an in-plane magnetic field and a perpendicular-to-plane current. Despite the complex multilayer geometry, clear microwave emission is observed for current densities in the interval of 9× 107 -13× 107 A cm-2. The emission frequency stays near 12 GHz when I< Ired =11.2× 107 A cm-2, then redshifts with a slope gradually reaching -350 MHzmA for 16× 107 A cm-2. The linewidth narrows exponentially to 3.8 MHz at 150 K for I< Ired, then broadens again as the emitted voltage redshifts. The temperature dependence of the linewidth exhibits a curvature change around the linewidth minimum.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)