Sm(Zr)Fe7Nx+αFe composite thin films were prepared on various substrates with differing values of thermal expansion from SmxFebalZry (11.3≦x≦17.8,0≦y≦3.2) targets by the rf sputtering method followed by annealing and nitrogenation. Their phase formation and magnetic properties were studied. All of the as-deposited films were amorphous, and the only films synthesized from the target with x=84 were crystallized into a composite of Sm(Zr)Fe7+αFe by annealing. Successive nitrogenation of the films with x=84 formed Sm(Zr)Fe7Nx+αFe composites whose grain diameter was estimated to be 30–50 nm. Despite the small coercivity of the prepared films, their recoil curves showed a remarkable spring-back phenomenon which originates in the exchange coupling between Sm(Zr)Fe7Nx and α Fe grains. The addition of Zr decreased the lattice constant, and choice of substrate did not affect the grain size. © 2000 American Institute of Physics.