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R. Sato Turtelli, J.P. Sinnecker, R. Grössinger, A. Penton-Madrigal, E. Estévez-Rams:
"Magnetic orderings and temperature dependence of the hysteresis loops of Nb_1−xFe_2+x";
Journal of Magnetism and Magnetic Materials, 316 (2007), S. e492 - e495.

Magnetic orderings and temperature dependence of the hysteresis loops of Nb_1−xFe_2+x

R. Sato Turtelli a, J.P. Sinnecker b, R. Grössinger a, A. Penton-Madrigal c and E. Estevez-Rams c

a Inst. f. Festkörperphysik, TU Wien, Wiedner Hauptsrasse 8-10, A-1040 Vienna, Austria
b Inst. de Física, UFRJ, CP 68528, 21945-970 Rio de Janeiro, Brazil
c Facultad de Física-IMRE, Univ. de la Havana, San Lazaro y L., CP 10400. Havana, Cuba

Abstract

Investigations of the magnetic properties of NbFe₂ were performed by measuring the temperature dependence of hysteresis loops, initial AC-susceptibility and zero field cooled (ZFC)-FC magnetizations in a wide field range of 50 Oe <= μ₀ <= 8000 Oe. Two well-defined peaks, at 4.8 and 21.4 K, were found in the AC-susceptibility curve, and only the first peak is sensible to a frequency change of the applied field. The peak changes to high temperature and its intensity decreases with increasing frequency, thus showing a relaxation phenomenon. In ZFC magnetization at 50 Oe, the peaks occur at 3.4 and 21.4 K. With increasing DC field, both peaks are shifted to low temperatures; however, the first peak disappears at fields higher than 100 Oe and a field higher than 1250 Oe suppresses the second peak. A third maximum merges from the magnetization curve at around 7 K in a field of 500 Oe, in which case, the maximum is suppressed by an external field higher than 4000 Oe. One can suggest that the ordered state of the stoichiometric NbFe₂ is a spin density wave (SDW) and both ferro- and antiferromagnetic spin fluctuations coexist.

NbFe₂; C14 Laves phase; Spin density wave; Spin fluctuation; Magnetization curve

http://dx.doi.org/10.1016/j.jmmm.2007.02.197

http://dx.doi.org/10.1016/j.jmmm.2007.02.197