The Cobalt Thickness Dependent Magnetic Properties of Pt/Co/Pt Thin Films

We investigate various magnetic properties of cobalt thin films with varying thicknesses by performing Brillouin light scattering spectroscopy. The thickness of the are deposited by using DC the magnetron sputtering system. By measuring the frequency of the propagating spin waves under different external magnetic fields, we analyze the magnetic characteristics of the Co thin films, such as the saturation magnetization and the perpendicular magnetic anisotropy energy. The determined saturation magnetization and surface perpendicular magnetic anisotropy energy density are approximately 994 +/- 30 kA/m and 0.73 +/- 0.01 mJ/m(2) , respectively. Additionally, we measure the spin wave frequencies for various cobalt film thicknesses and it is directly compared with the analytically calculated values. Comparing the measured spin wave frequencies with analytically calculated spinwave frequencies, it is found that for spin waves in magnetic films up to approximately 5 nm thick, considering only the perpendicular magnetic anisotropy energy is sufficient. However, for spin waves in magnetic thin films thicker than 5 nm, which include perpendicular magnetic anisotropy energy, a careful approach is required depending on the boundary conditions such as exchange and dipole interactions.