An enthalpy of solution of platinum in iron studied by 57Fe Mossbauer spectroscopy

The room temperature Mossbauer spectra of Fe-57 were measured for iron-based solid solutions Fe1-xPtx with x in the range 0.01 <= x <= 0.05. The obtained data were analysed in terms of the binding energy E-b between two platinum atoms in the studied materials using the extended Hrynkiewicz-Krolas idea. It was found that for x < 0.05 the energy is positive or Pt atoms interact repulsively. The extrapolated value of E-b for x = 0 was used for computation of the enthalpy HFe-Pt of solution of platinum in iron. The result HFe-Pt = -0.62(16) eV/atom was compared with the corresponding values resulting from the semi-empirical Miedema's model of alloys and the proper data obtained with Calphad's calculations as well as theoretical computations on the basis of the modified embedded-atom model. The comparison shows that all mentioned values of HFe-Pt are in a qualitative agreement i.e. they are negative, and moreover our findings agree also quantitatively with the Miedema's model predictions.