Crystal structure and microwave permeability of very thin Fe-Si-Al flakes produced by microforging

摘要: Fine flakes of Fe–Si–Al produced by long-duration microforging exhibit a peculiar dual-peak dispersion in their frequency characteristics the imaginary part permeability. This dual has high potential to be electromagnetic noise suppressor, works effectively microwave band. In previous report we clarified that one dispersions (D II), which appears lower range, is correlated shape anisotropy flakes. this article, origin another III) studied analyses crystalline structure changes during forging (100–180 h) and annealing processes. X-ray diffraction Mossbauer spectra strongly suggest annealed have composition gradient consisting an Fe-rich mother phase Si/Al-rich surface layer. The fact D III enhanced with development separation leads conclusion caused magnetoelastic near flake surface.