Morphological Structure and Magnetic Properties of FeTaN Films

Nanocrystalline FeTaN thin films with a high Ta content were prepared in a reactive magnetron sputtering system. The as-sputtered films consist of the amorphous phase. The morphological structure and magnetic properties were investigated. Nanocrystalline α-Fe grains with the (110) plane parallel to the film surface crystallize from the amorphous phase after proper annealing. The film sputtered in low nitrogen partial pressure exhibits excellent soft magnetism because the α-Fe grains crystallized only with grain size less than the ferromagnetic exchange length. Nitrogen atoms play an important role in refining the α-Fe grains and inducing uniaxial anisotropy in the Fe–Ta–N films.