Thermal scanning studies of percolated Fe–Cu granular alloys

L.M. SOCOLOVSKY, F.H. SANCHEZ

MATERIALS CHARACTERIZATION

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2003 vol. 50 p. 123 - 125

1044-5803

Fe–Cu alloys produced by mechanical alloying were studied with Mo¨ssbauer thermal scanning spectroscopy (MTS). This technique consists in recording Mo¨ssbauer effect absorption at a fixed energy while the temperature of the sample is changed. Hyperfine magnetic field behavior can be closely followed. Four mechanically alloyed samples FexCu100 x with iron concentration x = 30, 35, 40, and 45 at.% were studied. Absorption graphs (intensity vs. temperature) are similar for all samples: intensity sharply falls with the increase of the temperature, following the collapse of the sextet lines. This collapse occurs at a very precise temperature, which coincides with a magnetic–nonmagnetic transition line in a former magnetic phase diagram. Conventional Mo¨ssbauer spectroscopy confirms the appointed phase change, displaying a doublet at temperatures above the critical.