Magnetic structure and magnetic properties of nanocrystalline and amorphous Fe–Zr–N films

Data on the magnetic structure and magnetic properties of Fe–Zr–N films, which were prepared by reactive magnetron sputtering of a heated target and deposited on glass substrates, are reported. Depending on the Zr content (from 3 to 35at%), the film compositions are characterized by Zr-to-N (at%) ratio from 0.3 to 36.5. The magnetic properties (saturation magnetization Ms, coercive field Hc) and magnetic structure (effective local magnetic anisotropy field D1/2Ha, grain size 2Rc, effective anisotropy field of stochastic domain D1/2〈Ha〉, relative stochastic domain size RL/Rc) of the films are discussed in interrelation with their phase and structural states. The coercive field of the studied ferromagnetic nanocrystalline films was shown to obey the relationship Hc~(2Rc)6 and depends on not only the grain size but also the local magnetic anisotropy field D1/2Ha. As the grain size of ferromagnetic phase decreases, the contribution of the magnetoelastic component to the coercive field decreases. It was shown, by examples of weak ferromagnetic and superparamagnetic films with amorphous and mixed (amorphous+nanocrystalline) structures containing a nonferromagnetic phase, that the magnetic properties reflect the real structural and phase state of the films, which cannot be revealed by the X-ray diffraction analysis.