IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Mossbauer Investigation of Fe–Mn–Cu Nanostructured Alloys Obtained by Ball Milling
Autor/es:
M. MIZRAHI; S. J. STEWART; A. F. CABRERA; J. DESIMONI
Revista:
HYPERFINE INTERACTIONS
Editorial:
Springer Netherlands
Referencias:
Año: 2006 vol. 161 p. 171 - 176
Resumen:
Fe79 Mn21 , (Fe79 Mn21 )90 Cu10 , and (Fe79 Mn21 )80 Cu20 , alloys, prepared by high energy ball milling were characterized by Mösssbauer spectroscopy, X-ray diffraction and ac-susceptibility. Results indicate that the Cu addition favors the formation of a FCC phase with two different magnetic states at room temperature, i.e., an antiferromagnetic and a paramagnetic one. Thermal evolution of the Mossbauer spectra revealed the occurrence of a magnetic ordering along a wide temperature range. This behavior is probably related to Fe atoms in FCC-Fe(Mn,Cu) phase having different environments and grain size distribution. Thermal dependence of in-phase ac-susceptibility shows that a long range ordering starts at 240 K for the Fe79 Mn21 alloy and shifts towards lower temperatures with the Cu content. These results would reflect a long-range magnetic ordering transition with a distribution of ordering temperatures rather than a blocking process of particle single-domains.