Low Laser Fluence Magnetization Precession in High Quality Cobalt/Palladium Multilayers

In this study, we have employed time-resolved photo-excited precession of magnetization (TRPEPM) to probe magnetic precession in several high-quality Co/Pd multilayers with different Co and Pd layer thicknesses (Co layer's thickness in the range of 0.25 - 0.78 nm and Pd layer's thickness in the range of 0.16 - 0.65 nm). We measured TRPEPM by employing a low laser fluence regime (< 7 μJ/cm^2) at room temperature. Co/Pd films are important materials for understanding low fluence optical excitation regime because of their high perpendicular magnetic anisotropy (PMA). This work aims to better illuminate this connection to understand the mechanism for photo-magnetic excitation and how it may be possible to effectively flip the magnetization in a non-thermal regime.