First principles calculations of lattice stabilities of complex structures
|Year of publication
|Article in Proceedings
|Proceedings of 34.International October Conference on Mining and Metallurgy
|MU Faculty or unit
|Physical chemistry and theoretical chemistry
|Lattice stability; ab initio calculations; complex structures
|The first principles calculation of total energies of complex phases have been addressed recently. The structural energy differences, calculated by FLAPW (Full potential augmented plane wave) method, enable us to utilise a more complex physical information about total energy of intermetallic phases and to propose a new model for their thermodyamic description. Our approach is based on two-sublattice model, similarly as for solid solution phases, but the structural energy differences for end-members in the metastable or unstable structures are obtained by means of first principles electronic structure calculations. Phase diagrams of Fe-Cr and Co-Cr systems containing the intermetallic sigma-phase (5 inequivalent lattice sites, 30 atoms in repeat cell) are described as an example of application of our new model.