High-induction nanocrystalline soft magnetic FeXTiYBZ films prepared by magnetron sputtering

To design films with the Fe/TiB2 nanocomposite structure, which are characterized by high saturation induction Bs, the phase and structural states and static magnetic properties of Fe‐TiB2 films prepared by magnetron sputtering and subjected to subsequent annealing have been studied. According to X‐ray diffraction data, either amorphous or nanocrystalline single‐phase structure (an α‐Fe(Ti,B) supersaturated solid solution with a bcc crystal lattice) is formed in the as‐sputtered films. Depending on the film composition, the grain size of the α‐Fe(Ti,B) phase varies from 45.6 to 6.5 nm; grains are characterized by high microstrain (0.21‐4.96%). The annealing at 200‐500 °C leads to a decrease in the lattice parameter of the α‐Fe(Ti,B) phase, i.e. to its depletion of titanium and boron and to the formation of two‐phase α‐Fe + Fe3B structure after annealing at 500 °C. The annealing at 200‐500 °C almost does not affect the grain size and microstrain of the bcc α‐Fe‐based phase. The amorphous state of the films is stable up to 500 °C. All studied films are ferromagnets; the saturation induction Bs(0.95‐2.13 T) and coercive field Hc (0.4‐5 kA/m) of the films were determined. Correlations between the Bs and Hc magnitudes and the chemical composition of the films, their phase and structural states and magnetic structure are discussed. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)