EN
The Gilbert damping for Co_2CrAl (Co_2Cr_{0.3}Fe_{0.7}Al) and Ni_2MnSn Heusler alloy films was investigated as a function of temperature. The best films reveals the Gilbert damping nearly independent of temperature. Magnetic relaxation in Co_2CrAl is strongly influenced by magnetic inhomogeneities due to phase separation. The best Ni_2MnSn epitaxial films have comparable Gilbert damping α of 6× 10^{-3} as half-metallic Co_2Cr_{0.3}Fe_{0.7}Al films with α = 3 × 10^{-3}.