Temperature investigations of magnetic properties when analyzing the structural phase state of a model nanocomposite with carbidosteel composition

Abstract

The phase composition, magnetic state of the phases and their influence on the formation of the magnetic hysteresis properties of the nanocomposite with the (Fe0.85Mn0.10Ni0.05)83C17 composition after mechanosynthesis and subsequent annealing have been studied. It is shown that, although the dependences of the coercive force on the annealing temperature H_c(Tann) of the alloy, measured at room and liquid nitrogen temperatures, are curves with maxima, the formation of Hc is driven by different mechanisms. At room temperature measurements, the maximum Hc value of the composite is obtained when the size of the ferrite phase precipitates approaches to the critical single-domain state, whereas at low temperature maximum Hc value is caused by the change of the cementite structural state upon annealing. Keywords: Nanocrystalline Fe-C-Mn-Ni alloys, mechanical alloying, heat treatment, X-Ray diffraction, coercive force, magnetic susceptibility, Curie temperature, Mossbauer spectroscopy.