Effect of nanoparticle size on magnetic damping parameter in Co92Zr8 soft magnetic films

► Co92Zr8 soft magnetic films with different nanoparticle size were prepared. ► Nanoparticle size dependence of static and dynamic magnetic properties was studied. ► Coercivity and magnetic damping parameter increase with increasing nanoparticle size. ► Enhancement of effective damping parameter mostly comes from extrinsic damping. ► Origin of increased extrinsic damping parameter is inhomogeneity of anisotropy.