Control of magnetization dynamics in Ni/sub 81/Fe/sub 19/ thin films through the use of rare-earth dopants

摘要: We show that the magnetization dynamics of soft ferromagnetic thin films can be tuned using rare-earth (RE) dopants. Low concentrations (2 to 10%) Tb in 50 nm Ni/sub 81/Fe/sub 19/ are found increase Gilbert magnetic damping parameter /spl alpha/ over two orders magnitude without great effect on easy axis coercivity or saturation magnetization. Comparison with Gd dopants indicates orbital character moment is important for transferring energy lattice. Structural transformations from crystalline amorphous state, observed first 2%-10% RE doping, may play a contributing but not sufficient role these films. The approach demonstrated here shows promise adjusting dynamical response, underdamped critically damped, film materials devices.