Thermodynamic studies of some Fe-Pt alloys by the solid electrolyte galvanic cell method

In the present investigation, the thermodynamic activities of iron in iron-platinum solid alloys were measured by the solid electrolyte galvanic cell method in the temperature range 1073-1273 K. The galvanic cell employed can be represented as (-) Pt, Fe(s), Feto(s) // ZrO2(11 mol pct CaO) // FetO(s), Fe-Pt alloys, Pt(+) The experimental set-up as well as the satisfactory performance of the galvanic cell were validated by measuring the standard Gibbs energy of formation of CoO in equilibrium with Cc in the same temperature range by replacing the working electrode by a Co, CoO mixture. 6 different Fe-Pt alloys covering the entire composition range were studied and the results are compared with earlier thermodynamic studies available in the literature. The present experimental results are found to be in general agreement with those of Alcock and Kubik. The values were fitted into a regular solution description in order to estimate the enthalpies of mixing Pt and Fe in the solid alloys.