Effect of the Cu concentration on the magnetic properties of mechanically alloyed FeMnCu system

M. MIZRAHI, F. CABRERA, AND J. DESIMONI

Buenos Aires

Workshop; At the Frontiers of Condensed Matter 2006; 2006

Effect of the Cu concentration on the magnetic properties of mechanically alloyed FeMnCu system M. Mizrahi, F. Cabrera, and J. Desimoni Departamento de Física, Facultad de Ciencias Exactas-UNLP, IFLP-CONICET C. C.N° 67, 1900 La Plata, Argentina. e-mail: desimoni@fisica.unlp.edu.ar  Magnetic nanoparticles materials are one of the topics under research, especially due to the production of a large variety of new structures with interesting physical properties. The investigation and improvement of these properties can lead to the discovery of novel magnetic materials with potential applications in new technologies. In order to get deeper into the knowledge of the nanoestructurated metallic systems, allowed powders of (Fe79Mn21)1-xCux (x = 0.2, 0.25 and 0.3) were prepared by milling the elemental species in a horizontal vibrating device with steel balls and vial, under Ar atmosphere during 15 h at 33Hz. The analysis of structural properties was carried out using X-ray diffraction (XRD). Measurements of AC-susceptibility, zero field cooling-field cooling (ZFC-FC) and M vs H cycles were also performed to obtain a magnetic characterization of the samples. The XRD results show only the presence of FCC-phase for the three concentrations. The AC-susceptibility curves show the existence of a characteristic temperature Tc which shifts to lower temperatures with the increase of the Cu content. The irreversibility of magnetic properties has been studied as function of the applied field to the ZFC-FC curves. The hysteresis loops, recorded at several temperatures, can be reproduced using three contributions, two magnetics and one non-magnetic. These results provide evidences for a highly disordered magnetic system with spin-glass-like behavior.