We study Gilbert damping in bulk metallic ferromagnets containing magnetic and nonmagnetic impurities in the presence of nonuniform magnetization precession. In this model, a microscopic expression for the Gilbert damping tensor is obtained using the linear response theory with respect to the interaction between magnetization and conduction electrons. We especially focus on a diagonal element of the tensor, which is a conventional Gilbert damping constant, and evaluate it numerically as a function of the wave vector q of magnetization precession. We show that the impurity scattering dominates Gilbert damping for 0 < |q| < k F↔ - k F↓, while the Stoner excitation dominates for k F↔ - k F↓ < |q| < k F↔ + k F↓ (k Fσ is the Fermi wave number for σ spin electrons).
- Gilbert damping
- Landau-Lifshitz-Gilbert equation
- Transverse spin susceptibility
ASJC Scopus subject areas
- Physics and Astronomy(all)