Magnetic interactions and exchange-bias in nanocomposite system (Fe<sub>1−x</sub>Co<sub>x</sub>)<sub>y</sub>(MnO)<sub>1−y</sub>
L R S Araújo; F L A Machado; L R S Araújo; Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901, Recife, Pernambuco, Brasil; F L A Machado; Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901, Recife, Pernambuco, Brasil
Журнал:
Journal of Physics: Conference Series
Дата:
2010-01-01
Аннотация:
The magnetization of the nanocomposite (Fe<sub>1−x</sub>Co<sub>x</sub>)<sub>y</sub>(MnO)<sub>1−y</sub> was investigated in the temperature (T) range 5–300 K and for applied magnetic fields (H) up to 2 T. The measurements were carried out in samples prepared by mechanical alloying with x 0.4 and 0.6, and y 0.35, 0.65 and 1. Room temperature Henkel plots indicated that the Fe<sub>1−x</sub>Co<sub>x</sub>nanoparticles interacts among each other predominantly through dipolar interaction. Furthermore, exchange-bias effect was observed for temperatures below the MnO Néel temperature (T<sub>N</sub> 117.7 K) with the corresponding exchange-bias field showing a significant increase with decreasing T. This trend was also followed by the coercive field. It was also observed below T<sub>N</sub> an irreversible behaviour in the zero-field- and field-cooled magnetizations.
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