Dependence of Magnetic Damping on Temperature and Crystal Orientation in Epitaxial Fe4N Thin Films

Abstract

In-plane and out-of-plane ferromagnetic resonance (FMR) were used to investigate the intrinsic magnetic damping constant () in epitaxial Fe4N thin films deposited on MgO substrates. The dependence of  on temperature was evaluated from room temperature (RT) to 4 K. The external magnetic field (H) of FMR was applied in two directions, i.e., [100] and [110], of the Fe4N lattice. Anisotropic  was observed from RT to 4 K. Moreover, the  for H // [100] exceeded the  for H // [110] at 180 K. Numerical calculations of  for bulk Fe4N revealed the same behavior as that in the experiments. The temperature dependence of anisotropic  was explained by the changes in the electronic band structure depending on the directions of magnetization.