Gilbert magnetic damping constant of epitaxially grown Co-based Heusler alloy thin films

The magnetic damping constant in a series of Co2MnAlxSi1-x and Co2FexMn1-xSi Heusler alloy epitaxial films were systematically investigated by using ferromagnetic resonance technique. The determined magnetic damping constant is roughly proportional to the density of states at the Fermi energy of the first principle calculation. The result is consistent with the theoretical prediction when taking spin-orbit interaction into account. The small Gilbert damping constant for the fabricated films other than the Co2FexMn1-xSi film with x>0.6 can be originated in the half-metallic electronic structure of Heusler alloys. (C) 2010 American Institute of Physics. [doi:10.1063/1.3456378]