Thermodynamic properties of dilute Co-Fe solid solutions studied by ⁵⁷Fe Mössbauer spectroscopy

The Co_1-xFe_x alloys where x ranges from 0.01 to 0.06 were measured at room temperature using transmission Mössbauer spectroscopy (TMS). The analysis of the obtained data allowed the determination of the short-range order (SRO), the binding energy E_b between two iron atoms in the studied materials using the extended Hrynkiewicz-Królas idea and the enthalpy of solution H_Co-Fe of Fe in Co. The results showed that the Fe atoms dissolved in a Co matrix interact repulsively and the estimated value of H_Co-Fe = -0.166(33) eV/atom. Finally, values of the enthalpy of solution were used to predict the enthalpy of mixing for the Co-Fe system. These findings were compared with corresponding data given in the literature, which were derived from calorimetric experiments and from the cellular atomic model of alloys described by Miedema.