Composition dependence of the Néel temperature and the entropy of the magnetic transition in the fcc phase of Fe-Mn and Fe-Mn-Co alloys

P. LA ROCA; P. MARINELLI; A. BARUJ; M. SADE; A. FERNÁNDEZ GUILLERMET

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2016 vol. 688 p. 594 - 598

0925-8388

Akey feature of the fcc-to-hcp martensitic transformation (MT) in Fe-Mn basedalloys is that the fcc structure is strongly stabilized by aparamagnetic-to-antiferromagnetic ordering reaction, which partially orcompletely inhibits the MT. In order to treat this phenomenon in thermodynamicterms it is necessary to account for the composition dependence of the Néeltemperature (TN) of the alloy and the entropy change (ΔSmg) associated to the loss of the antiferromagneticordering. In the present work the composition dependence of these properties inFe-Mn and Fe-Mn-Co alloys have been established by performing systematicmeasurements of the heat capacity. The current results are critically comparedwith experimental data from the literature, as well as estimates andcorrelations based on previous analyses by the present authors. The relevanceof the reported data for the understanding of the fcc-to-hcp MT in the Fe-Mnand Fe-Mn-Co alloys is highlighted.