STRUCTURAL AND SOFT MAGNETIC-PROPERTIES OF FE/FE-HF-C MULTILAYERED FILMS WITH THE HIGH BS AND THERMAL-STABILITY

Fe/nanocrystalline-Fe-Hf-C multilayers were prepared by annealing sputter-deposited Fe/amorphous-Fe-Hf-C multilayers. The grain size of the Fe layer is also refined by the multilayer effect. The columnar growth is interrupted even by a very thin Fe-Hf-C layer, when epitaxial growth of the crystalline phase on the Fe layer in the early stage of the amorphous Fe-Hf-C layer deposition is prevented. The annealed multilayers have good soft magnetic properties (\mu\1 MHz = 6000 max., H(c) = 9.6 A/m min.) as well as high-saturation flux density (B(s) = 1.9-2.1 T). Furthermore, the soft magnetic properties were maintained even after annealing at 1031 K. This high thermal stability is probably due to the extremely fine and stable HfC particle dispersed in the Fe-Hf-C layer.