Co-Mo thin films with an artificially layered structure

Cobalt-molybdenum (Co-Mo) thin films deposited into an alternating multilayer structure by a dc-magnetron sputtering method have a compositionally modulated structure. Films with thicker Co layers than Mo layers have an artificial superlattice hcp structure with the c-axis normal to the film plane. Films with reverse thicknesses of Co and Mo have an artifical superlattice bcc structure with the 〈110〉 axis normal to the film plane. Films are ferromagnetic with an easy magnetization direction in the film plane. The Co layers in contact with Mo layer have reduced magnetization. The paramagnetism or nonmagnetism is observed in films with a small periodicity composed of thinner Co layers than Mo layers. The small magnetization is originated from both low Curie temperature and decrease in the magnetization due to lattice deformation of Co.