Magnetostriction of multilayer Ni-C films

Multilayer Ni-C films have been prepared using d.c. triode sputtering with a fixed C layer of 2 nm thick and wlth Ni layer varying from 5 to 100 nm thick. The C layer is amorphous and the structure of Ni layer is hexagonal for 5nm thick but becomes f.c.c. when the thickness is above 6 nm. The magnetization is strongly reduced which is attributed to the presence of nonmagnetic layers at each interface. These layers could be Ni3C. The magnetostriction of the investigated films was measured at room temperature using the strain modulated ferromagnetic resonance method. The square dependence of magnetostriction constant on saturation magnetization was obtained.