Model for predicting atomic substitutions in intermetallic compounds

A thermodynamic model was developed for calculating the probabilities of at omic substitutions in different sites in intermetallic compounds. The model considers three contributions: chemical, elastic and structural, in calcul ating the changes that occur in the enthalpy due to the atomic substitution s at different sites in intermetallic compounds. The model was tested for o ver forty rare-earth containing compounds such as Nd-2(Fe,X)(17)(C), Nd-2(F e,X)(14)B, R(Fe,X)(12), R(Al,X)(12), Nd-3(Fe,X)(29) and Er(Ni,X)(5) where X is the substituent atom. Comparison of the model calculations with results obtained from neutron diffraction show that the model precisely determines the sites preferentially occupied by the X atoms. (C) 2000 American Instit ute of Physics. [S0021-8979(00)89408-6].