Magnetic structure of FexCu100 x magnetoresistive alloys produced by mechanical alloying

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

Hyperfine Interactions

Springer

Año: 2001 vol. 133 p. 47 - 52

0304-3843

Fex Cu100−x magnetoresistive alloys were produced by mechanical alloying. X-ray dif-fraction shows fcc structure. The room-temperature Mössbauer spectra evolves from an asymmetricaldoublet below x = 25%, to a broad magnetic hyperfine field distribution above this concentration.Quadrupole splitting of the doublet varies between 0.48 and 0.57 mm/s, and its isomer shift from0.16 to 0.29 mm/s. Low-temperature Mössbauer spectroscopy displays a Bhf distribution. Magneti-zation measurements display different features depending on concentration, from mictomagnetism toferromagnetism. Low-temperature magnetoresistance is measured. Samples with x ∼ 20% exhibitlarger magnetoresistivity ratios. Bulk and hyperfine magnetic properties are correlated in order toexplain magnetoresistivity features of these samples.