X-ray diffraction in amorphous microwires (Fe75.5B13Si11Mo0.5): influence of their geometry

The microstructural characteristics of glass coated microwires, Fe75.5B13Si11Mo0.5, are studied by wide angle X-ray scattering (WAXS) considering their geometry determined by their fabrication. The raw WAXS data show three wide diffraction peaks corresponding to different structural correlations, whose first and second ones correspond to long correlation distances in the Pyrex layer (≈3.5 Å) and in the metallic core (≈2.0 Å). The high q width peak (≈1.5 Å) seems to be formed by an overlapping of two peaks associated to short correlation distances in the layer and in the core. The diffraction patterns normalized to absolute units show that the higher the ρ ratio the higher the intensity of the core peaks and the lower the intensity of the layer peaks. From the peaks corresponding to the metallic core, we can deduce small (although systematic) changes of the short-range order in the glassy metallic core of the microwires.