Thermodynamic assessment of the Fe-Nb system

The Gibbs energy of formation of the solution and compounds phases in the Fe-Nb system were derived from an optimization procedure using all the available experimental thermodynamic and phase diagram data. The thermodynamic description of the stoichiometric and non-stoichiometric compounds was made using two, three or four sublattice models, while a Redlich-Kister polynomial was used for the solution phases.