Magnetic Properties of FeCo Films Prepared by Co-Sputtering and Hydrogenous Gas Reactive Sputtering

In this experiment, we have added carbon into FeCo films by two kinds of sputtering processes: the first is the conventional process of co-sputtering, the second is introducing hydrogenous gas (acetylene gas in this experiment) into the chamber during sputtering. The crystallographic, microstructure, and magnetic properties of the films have been compared. Although nano-crystalline films, which have much lower coercivity according to the random anisotropy theory proposed by Herzer in 1990, can be prepared by both processes, magnetic properties of the films prepared by the two processes are different. Magnetic soft films are successfully prepared with coercivity about 1 Oe, saturation magnetization about 23.5 kG, and real part permeability as large as 1200-1500 in the frequency range up to 2.6 GHz. X-ray photoelectron spectroscopy results show films deposited without hydrogenous gas have oxygen contamination as high as 3 at%. Oxygen-free films are found to be prepared with the introducing of acetylene gas during the sputtering process.