Magnetic and Elasto Optic Dynamic on Co/Pt Multlayers

Thin Co/Pt multi-layers with a Pt cap-layer were grown with different capping layer thickness (3 nm< d <20 nm) over a Si02/Si substrate in order to stabilize the perpendicular anisotropy, as well as to control the spin pumping process. On the other hand, Pt layer enhance the damping factor for the magnetization relaxation. Also the Pt capping layer, form a cavity that may be used to generate coherent phonons wave. We show by time resolved spectroscopy, the magnetic relaxation damping rate and the phonon waves properties in these Co/Pt multi-layers.