Synthetic first-principles studies from phase equilibria to microstructural formation in the Fe-Pt L10 phase

Electronic-structure calculations, the cluster-variation method of statistical mechanics, and the phase-field method were combined in attempted first-principles calculations of phase equilibria and microstructural evo-lution associated with the disorder-L10 transition of the Fe-Pt system. The calculated disorder-L1(0) transition temperature was within similar to 10 K difference from the experimental value, and the locus of spinodal ordering temperature is placed in the phase diagram. The calculated microstructure demonstrates preferential growth of the ordered domain along the <100> direction and, in the later period, an anisotropic morphology of an antiphase domain structure develops. We offered an interpretation from the atomistic point of view for this morphology. We therefore achieved consistent first-principles multiscale calculations of phase equilibria and microstructural evolution, bridging microscopic to mesoscopic scales without any adjusting parameters.

Automated summary

The combination of electronic-structure calculations, the cluster-variation method, and the phase-field method was used to calculate the phase equilibria and microstructural evolution of the disorder-L10 transition in the Fe-Pt system. The calculated transition temperature was close to the experimental value, and the spinodal ordering temperature was determined. The microstructure showed preferential growth of ordered domains along the <100> direction and the development of an anisotropic morphology of an antiphase domain structure. The calculations provided an atomistic interpretation of this morphology, offering consistent first-principles multiscale calculations without any adjusting parameters.