Effect of seed layers on dynamic and static magnetic properties of Fe₆₅Co₃₅ thin films

Fe₆₅Co₃₅ thin films have been deposited on SiO₂ substrates using sputtering technique with different choices of seed layer; Ru, Ni_82.5Fe_17.5, Rh, Y and Zr. Best soft magnetic properties were observed with seed layers of Ru, Ni_82.5Fe_17.5 and Rh. Adding these seed layers, the coercivity of the Fe₆₅Co₃₅ films decreased to values of around 1.5 mT, which can be compared to the value of 12.5 mT obtained for films deposited without seed layer. Further investigations were performed on samples with these three seed layers in terms of dynamic magnetic properties, both on as prepared and annealed samples, using constant frequency cavity and broadband ferromagnetic resonance measurements. Damping parameters of around 8.0 10⁻³ and 4.5 10⁻³ were obtained from in-plane and out-of-plane measurements, respectively, for the as prepared samples, values that were reduced to about 6.5 10⁻³ and 4.0 10⁻³ for annealed samples. (paper)