Thickness and temperature-dependent damping in La_0.67Sr_0.33MnO₃ epitaxial films

Damping of La_0.67Sr_0.33MnO₃ (LSMO) epitaxial films as a function of thickness at different temperatures was studied. The competition between two scattering types (⁠ $ρ$-like and $σ$-like) with entirely distinct thickness and temperature dependencies resulted in complicated damping behavior. The behavior of $σ$-like damping in LSMO films is consistent with the behavior in magnetic metal films. However, because $ρ$-like damping is sensitive to the fine electron structure near the Fermi surface, the distortion of the oxygen octahedra controlled by the film thickness is an important factor in controlling the damping. Our study demonstrates that the complexity of damping in LSMO epitaxial films is a consequence of strong-correlation effects, which are characteristics of complex transition-metal oxides.