From Fe3Si towards Fe3Ge in Finemet-like nanocrystalline alloys: Mössbauer spectroscopy

Nanocrystalline Finemet-type ribbons with different Si/Ge ratio [Fe73.5Si13.5−xGexNb3B9Cu1 (x=7x=7, 8, 10 and 13.5)] were studied by means of Mössbauer spectroscopy and X-ray diffraction. The trend to form the non-stoichiometric DO3 Fe3Si structure in Finemet alloys (x=0x=0) is confirmed as Si is substituted for Ge. Results also indicate that the crystalline fraction increases when Si is gradually replaced with Ge. The hyperfine magnetic fields and the isomer shifts are characterised by a quasi-linear relationship with the Ge content of the nanocrystals.