Milling time effects on the hyperfine properties of FeCuB alloys.

A Mössbauer study of (Fe30Cu70)96B4 (FeCuB) alloys, obtained previously by induction casting and subsequent ball milling up to 60 h, was conducted at room temperature (RT). 57Fe Mössbauer spectra were fitted using three components: two magnetic hyperfine field distributions (HFD) with average Bhf1 and Bhf2 values plus a quadrupolar distribution (QSD) to account for disorders that are induced during the milling process. Thus, these components are respectively associated with a magnetically coupled α-iron phase (Bhf1 component), a Fe-rich containing phase with Bhf2 value smaller than that found for α-Fe (Bhf1 component), consequently attributed to the FeCuB alloy and, a Fe-poor phase responsible for the paramagnetic phase (QSD). The Bhf2 component shows fcc-type features, and the milling process produces an increase of the paramagnetic phase at the expense of the α-iron (bcc). [ABSTRACT FROM AUTHOR]