Low Gilbert damping and linewidth in magnetostrictive FeGa thin films

•High-quality Galfenol thin films have been fabricated on MgO substrate by Sputter Beam Epitaxy.•FMR spectroscopy demonstrates low effective damping parameter and narrow linewidth.•Magnetometry and FMR reveals low coercivity as well as expected in-plane anisotropy.•Galfenol thin films may be a promising candidate for low loss microwave devices.