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 Ni
3
C. 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.