Magnetization dynamics and cone angle precession in permalloy rectangles

Magnetization dynamics in pairs of submicrometer-sized permalloy rectangles are studied by means of broadband-ferromagnetic resonance measurements. The coupling strength of neighboring elements depends on their center-to-center distance. The stray field of one rectangle decreases the local effective field at the position of the other rectangle. Pairs consisting of two different rectangles, like in a conventional all-metal lateral spin-valve device, are studied. Moreover, the cone angles of the precessional motion of the magnetization at ferromagnetic resonance are determined using transport measurements. Large cone angles of up to 13.7^∘ are realized in a sample geometry that permits electrical insulation together with a small distance between the permalloy rectangles and the exciting coplanar waveguide.