Investigation of anisotropic effective magnetic damping in epitaxial La0.67Sr0.33MnO3 film

La_0.67Sr_0.33MnO₃ (i.e., LSMO), a perovskite semi-metal oxide, is renowned for its high spin polarization, elevated Curie temperature, and notably low Gilbert damping, making it a promising candidate for spintronics applications. In this study, anisotropic Gilbert damping was experimentally observed in a 20-nm thick epitaxial single-crystal LSMO/STO (sub.) film deposited by using pulsed laser deposition (PLD), exhibiting a combination of uniaxial and fourfold anisotropies, using broadband ferromagnetic resonance (FMR) at 300 K. The behavior of the damping coefficient α, suggests that Gilbert damping in the LSMO film predominantly arises from two-magnon scattering. Remarkably, the anisotropic effective damping showed a significant increase, from 125 to 229%, across the easy and hard magnetic axes as the temperature decreased from 300 K to 100 K. Additionally, an enhanced peak of the Gilbert damping is observed as the temperature rises to approximately 150 K, likely due to a spin reorientation transition at the LSMO/STO interface. These findings underscore the potential of LSMO thin films in spintronic devices requiring tunable magnetic damping properties.