Low damping and small inhomogeneous linewidth broadening in Co2 FeAl films

In this work we investigate structural, static and dynamics magnetic properties of Co2 FeAl (CFA) films, deposited on Si (1 0 0) with Ti buffer and capping layers. We study the evolution of the coercive field, anisotropies, damping constant and linewidth broadening as a function of CFA film thickness in the range 5 nm to 200 nm. We obtain coercive fields weakly dependent on thickness, with values in the range 4.2 Oe to 7.8 Oe. All samples show roughly constant in-plane magnetic anisotropy, and out-plane anisotropy originated from the CFA/Ti interfaces. With increasing thickness we observe the emergence of rotatable anisotropy. We found magnetic damping parameters α between 2.56 × 10-3 and 3.45 × 10-3, and inhomogeneous linewidth ΔH0 under 10.3 Oe for the whole range of CFA film thickness. These ΔH0 results are small when compared to the values reported for CFA in literature, specially for films with thickness above 100 nm. The present study contributes to a better understanding of the dynamic properties of magnetic CFA films, and open new potential applications in magneto-impedance sensors, RF shielding and others.