Carbon additive effects on the nanostructure and magnetic property of the Co–Fe–Zr–B–C films

In this study, the carbon additive Co–Fe–Zr–B alloy films were prepared by dual-gun co-sputtering. The effects of the carbon addition and heat treatment on the nanostructure and magnetic properties of the Co–Fe–Zr–B–C alloy films are reported. The experimental results show that a crystalline (Co, Fe) phase formed after heat treatment at 400 in the Co–Fe–Zr–B–C films with low carbon additive level. Carbon atoms inhibited the crystallization of the as-deposited Co–Fe–Zr–B–C films. From the TEM observation, the nanostructures, such as the atomic structure and grain sizes, showed a strong carbon content dependence. The coercivities of the Co–Fe–Zr–B–C films annealed at 400 varied from 18 to 0.3 Oe with the increasing carbon addition. However, the films annealed at higher temperature exhibited a dramatic increase in the coercivities, which correlated to the formation of the crystalline (Co, Fe) phase. The resistivities of the Co–Fe–Zr–B–C films relied on the carbon contents rather than on annealing temperatures.