# Physics of Metals and Metallography (v.117, #13)

Ab initio modeling of decomposition in iron based alloys by O. I. Gorbatov; Yu. N. Gornostyrev; P. A. Korzhavyi; A. V. Ruban

*(1293-1327)*. This paper reviews recent progress in the field of

*ab initio*based simulations of structure and properties of Fe-based alloys. We focus on thermodynamics of these alloys, their decomposition kinetics, and microstructure formation taking into account disorder of magnetic moments with temperature. We review modern theoretical tools which allow a consistent description of the electronic structure and energetics of random alloys with local magnetic moments that become totally or partially disordered when temperature increases. This approach gives a basis for an accurate finite-temperature description of alloys by calculating all the relevant contributions to the Gibbs energy from first-principles, including a configurational part as well as terms due to electronic, vibrational, and magnetic excitations. Applications of these theoretical approaches to the calculations of thermodynamics parameters at elevated temperatures (solution energies and effective interatomic interactions) are discussed including atomistic modeling of decomposition/clustering in Fe-based alloys. It provides a solid basis for understanding experimental data and for developing new steels for modern applications. The precipitation in Fe–Cu based alloys, the decomposition in Fe–Cr, and the short-range order formation in iron alloys with*s–p*elements are considered as examples. Magnetism of metals in the dynamic spin-fluctuation theory by N. B. Melnikov; B. I. Reser

*(1328-1383)*. We overview new developments in spin-fluctuation theory, which describes magnetic properties of ferromagnetic metals at finite temperatures. We present a detailed analysis of the underlying techniques and compare numerical results with experiment.

**Keywords:**dynamic susceptibility; spin-density correlations; magnetic properties; ferromagnetic metals and alloys