Spin Relaxation from Continuous Film to Magnetic Nanostructures

The spin relaxation from continuous iron film, to lithographically patterned submicron Permalloy disks, and to iron and nickel nanoparticles were studied by ultrafast magnetooptical technique. In the continuous film, the damping parameter is obtained through fitting the experimental data. In the lithographically confined submicron disks, the excitation due to the formation of the standing waves is found. Ultrafast spin relaxation and spin relaxation due to magnetic coupling are investigated.