A Study of Thermodynamic Properties of Dilute Fe–Pd Alloys by the 57Fe Mössbauer Spectroscopy

Room-temperature Mössbauer spectra of 57Fe were recorded for iron-based solid solutions Fe1-xPdx with x in the range 0.010 ≤ x ≤ 0.066. The obtained data were analysed in terms of the binding energy Eb between two palladium atoms in the studied materials using the extended Hrynkiewicz–Królas idea. It was found that the energy is positive, which indicates that Pd atoms interact repulsively. The extrapolated value of Eb for x = 0 was used to compute the enthalpy of solution HFe-Pd of palladium in iron. It turned out that the value of HFe-Pd determined on the basis of the 57Fe Mössbauer spectra is in qualitative agreement with the corresponding value derived from Miedema's model of alloys and is at variance with the available calorimetric data for the Fe–Pd system.