Magnetic structure of FexCu100-x magnetoresistive alloys produced by mechanical alloying

L.M.SOCOLOVSKY, F. H. SÁNCHEZ, Y P.SHINGU

HYPERFINE INTERACTIONS

Springer

Año: 2001 vol. 133 p. 47 - 52

0304-3843

FexCu100-x magnetoresistive alloys were produced by mechanical alloying. X-ray diffraction shows fcc structure. The room temperature Mössbauerspectra evolves from an asymmetrical doublet below x=25% to a broad magnetic hyperfine field distribution above this concentration. Quadrupolesplitting of the doublet varies between 0.48 and 0.57 mm/s and its isomer shift from 0.16 to 0.29 mm/s. Low temperature Mössbauer spectroscopy displays a Bhf distribution. Magnetization measurements display different features depending on concentration, from mictomagnetism to ferromagnetism. Low-temperature magnetoresistence is measured. samples with x = 20 % exhibit larger magnetoresistivity ratios. Bulk and hyperfine magnetic properties are correlated in order to explain magnetoresistivity features of these samples.