Magnetic and structural properties of magnetoresistive FexAu100
x alloys produced by mechanical alloying

L. M. SOCOLOVSKY, F. H. SANCHEZ, P.H. SHINGU

PHYSICA B - CONDENSED MATTER

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2002 vol. 320 p. 149 - 152

0921-4526

FexAu100x alloys have been produced for the first time by mechanical alloying. X-ray diffractograms show FCC peaks. From the X-ray diffracion peak-widths we estimate the final grain size, which vary with x from 112nm (for x ¼ 15) to 32nm (for x ¼ 30). Lattice parameter decreases with concentration (minimum 0.401nm at x ¼ 30), but above Vegard?s law values. Susceptibility measurements show cluster-glass behaviour. Critical temperatures are consistently lower than similar alloys produced by arc melting followed by fast quenching. A magnetic phase diagram ispresented. Giant magnetoresistance is present in all samples, with a maximum at x ¼ 25: This effect is caused by the dispersion of small iron clusters produced by the mechanical work.