TY - JOUR

T1 - Characterization of magnetic phases in the FexMn0.65-xAl0.35 disordered alloys

AU - Zamora, Ligia E.

AU - Pérez Alcázar, G. A.

AU - González, C.

AU - Greneche, J. M.

AU - Aguirre, W. R.

AU - Bohórquez, A.

AU - Baggio Saitovich, E. M.

AU - Sánchez, D.

N1 - Funding Information:
The authors are grateful to the Universidad del Valle and Colciencias, Colombian Agency, for partial financial support. C.G. would like to thank the support of Laboratoire de Physique de l’Etat Condensé, Université du Maine, for a research stay. G.A.P.A. would like to thank the support of Centro Brasileiro de Pesquisas Físicas and to CLAF, Centro Latinoamericano de Física, for the research stay and grant, respectively. The present study work was supported by the ECOS-Nord Colombian French exchange program under contract CF99P04.

PY - 2006/6

Y1 - 2006/6

N2 - Melted alloys of the FexMn0.65-xAl0.35 disordered system, 0.25{less-than or slanted equal to}x{less-than or slanted equal to}0.65, were experimentally studied by Mössbauer spectrometry, vibrating sample magnetometry and AC magnetic susceptibility. All the alloys exhibit the BCC structure with a nearly constant lattice parameter (2.92 Å). Mössbauer studies at room temperature (RT) show that in the 0.25 {less-than or slanted equal to}x{less-than or slanted equal to}0.45 range the alloys are paramagnetic (P) while in the 0.50{less-than or slanted equal to}x{less-than or slanted equal to}0.65 range, they are ferromagnetic. At 77 K, Mössbauer studies show that the alloy with x = 0.25 presents weak magnetic character that is consistent with an antiferromagnetic (AF) behavior due to the high Mn content, while those with 0.30{less-than or slanted equal to}x{less-than or slanted equal to}0.40 are paramagnetic, and those in the 0.45{less-than or slanted equal to}x{less-than or slanted equal to}0.65 range are ferromagnetic (F) with a mean field increasing with the Fe content. Hysteresis cycles at RT prove the paramagnetic character of the alloys between x = 0.25 and 0.40 and the ferromagnetic character for x {greater than or slanted equal to} 0.45. Complementary measurements using AC magnetic susceptibility permit a magnetic phase diagram to be proposed, with the P phase for high temperature and all the compositions, the AF phase for low Fe content and at low temperature, the F phase for high Fe content above RT and the spin glass phase for all the compositions and at temperatures lower than 46 K. In addition, the mean field renormalization group (MFRG) method, applied to a random competitive and site dilute Ising model with nearest-neighbor, gives rise to magnetic phase diagram, which fairly agrees with previous experimental one.

AB - Melted alloys of the FexMn0.65-xAl0.35 disordered system, 0.25{less-than or slanted equal to}x{less-than or slanted equal to}0.65, were experimentally studied by Mössbauer spectrometry, vibrating sample magnetometry and AC magnetic susceptibility. All the alloys exhibit the BCC structure with a nearly constant lattice parameter (2.92 Å). Mössbauer studies at room temperature (RT) show that in the 0.25 {less-than or slanted equal to}x{less-than or slanted equal to}0.45 range the alloys are paramagnetic (P) while in the 0.50{less-than or slanted equal to}x{less-than or slanted equal to}0.65 range, they are ferromagnetic. At 77 K, Mössbauer studies show that the alloy with x = 0.25 presents weak magnetic character that is consistent with an antiferromagnetic (AF) behavior due to the high Mn content, while those with 0.30{less-than or slanted equal to}x{less-than or slanted equal to}0.40 are paramagnetic, and those in the 0.45{less-than or slanted equal to}x{less-than or slanted equal to}0.65 range are ferromagnetic (F) with a mean field increasing with the Fe content. Hysteresis cycles at RT prove the paramagnetic character of the alloys between x = 0.25 and 0.40 and the ferromagnetic character for x {greater than or slanted equal to} 0.45. Complementary measurements using AC magnetic susceptibility permit a magnetic phase diagram to be proposed, with the P phase for high temperature and all the compositions, the AF phase for low Fe content and at low temperature, the F phase for high Fe content above RT and the spin glass phase for all the compositions and at temperatures lower than 46 K. In addition, the mean field renormalization group (MFRG) method, applied to a random competitive and site dilute Ising model with nearest-neighbor, gives rise to magnetic phase diagram, which fairly agrees with previous experimental one.

KW - Alloys

KW - Hyperfine interactions

KW - Magnetization

KW - Mechanical alloying

UR - http://www.scopus.com/inward/record.url?scp=33747764260&partnerID=8YFLogxK

U2 - 10.1016/j.jmmm.2005.08.005

DO - 10.1016/j.jmmm.2005.08.005

M3 - Artículo en revista científica indexada

AN - SCOPUS:33747764260

SN - 0304-8853

VL - 301

SP - 495

EP - 502

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

IS - 2

ER -