Study of mechanically alloyed nano Cu-Fe particles with a heterostructure

The magnetic alloys of Cu-Fe (Cu50Fe50, Cu80Fe20 and Cu90Fe10) were prepared by a mechanical alloying method and their structural and magnetic behaviors were examined by X-ray diffraction and Mossbauer spectra. The magnetization curves did not distinctly show the saturation at 70 kOe for the concentrated alloys of Cu80Fe20 and Cu90Fe10. The Mossbauer spectrum of Cu80Fe20 at room temperature shows one Lorentzian line of the paramagnetic phase, whereas the Mossbauer spectrum of Cu90Fe10 consists of a sextet Lorentzian line at room temperature and a centered doublet line. The Mossbauer spectra of Cu90Fe10 measured in the temperature ranges from 13 to 295 K, implies that Cu90Fe10 consists of two magnetic phases. One superimposed sextet corresponds to the ferromagnetic iron in Cu matrix and the other one indicates the superparamagnetic iron rich phase. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.