Applications of solid electrolytes in thermodynamic studies of materials: A review

Corrosion-Free EMF Measurements of Zinc-Based Intermetallic Compounds at Ambient Temperature

Material development requires in many cases information about the necessary stability of the materials against oxidation, which is encoded in the chemical activity of the constituting elements. Determination of the chemical activity is tedious, especially for metallic materials at or close to ambient temperature. To determine the chemical activity of Zn at ambient temperature, electromotive force (EMF) measurements on the intermetallic compounds ZnPd, ZnPt and Cu₅Zn₈ within their respective homogeneity range were conducted. The single‐phase nature of the samples was confirmed by powder X‐ray diffraction, light microscopy as well as SEM/EDX analysis. To exclude oxidation, and therefore faulty determination of the electrochemical potentials, a method was developed to conduct the electrochemical measurements under non‐corrosive conditions in inert atmosphere. Corrosion by the electrolyte was avoided using anhydrous dimethylformamide as aprotic solvent. From the EMF the respective intrinsic activities of zinc in the corresponding intermetallic compounds was determined. Measurements on Cu₅Zn₈ and comparison to available data in literature verified the developed method allowing to retrieve thermodynamic data of ZnPd and ZnPt for the first time at ambient temperature. The herein developed and easy‐to‐use methodology is applicable to a wide range of metallic material by choosing appropriate compositions of the electrolyte and has the potential to boost material development.

The rare earth ruthenium pyrochlore Ho2Ru2O7(s): thermodynamic properties by electrochemical cell and differential scanning calorimetric measurements

The Gibbs energy of formation of Ho₂Ru₂O₇(s) has been determined using a galvanic cell and by employing an oxide ion conducting electrolyte.

Thermodynamic stability and impedance measurements of perovskite LuRhO3(s) in the Lu–Rh–O system

The Gibbs energy of formation of LuRhO₃(s) has been determined using a solid-state electrochemical technique employing an oxide ion conducting electrolyte.

Thermodynamic investigations of ternary liquid alloys

A review of different methods for determining thermodynamic quantities is given. The electromotive force (EMF) method with a liquid and solid electrolyte, the calorimetric and differential scanning calorimetry (DSC) methods, and vapour pressure experiments like the isopiestic and Knudsen effusion methods are discussed.