Magnetic properties of FeCoC thin films prepared by various sputtering methods

In order to grow nanocrystallized soft magnetic thin films, FeCoC alloys were first deposited by reactive sputtering in Ar/C2H2 plasma. This deposition process rendered it possible to incorporate a carbon content between 0 and 30 at.% into the FeCo samples. The films were then compared to FeCoC samples obtained from a Fe65Co35/C composite target, with an adjustable amount of C slots. Layers with soft magnetic properties were achieved when increasing the C2H2 rate during the reactive deposition, whereas films deposited by sputtering of FeCo and C on the same target demonstrated a very high coercivity. Permeability spectra measurements (and published elsewhere) demonstrated that FeCoC prepared with acetylene is a very promising material for high-frequency magnetic devices.