Eur. Phys. J. Special Topics 229, 295-304 (2020)
https://doi.org/10.1140/epjst/e2019-900110-y

Regular Article

Thermodynamically stable compositional inhomogeneous zones in the process of spinodal decomposition

¹ Udmurt Federal Research Center of the Ural Branch of the Russian Academy of Sciences, Baramzinoy str. 34, 426067 Izhevsk, Russia
² Udmurt State University, Department of Mathematics, Computer Engineering and Physics, Universitetskaya str. 1, 426067 Izhevsk, Russia

^a e-mail: lomaevst@udman.ru

Received: 16 June 2019
Received in final form: 17 July 2019
Published online: 11 February 2020

Abstract

We have marked out an important thermodynamic deficiency of the Cahn-Hilliard model and now suggest a theoretical model of compositional inhomogeneous zones (CIZ) associated with spinodal decomposition and other spinodal phenomena, to avoid such deficiency. The suggested model proves thermodynamic stability of single-phase state with the CIZ. Within the isotropic approximation, the CIZ are represented as a wave-packet of concentration waves, with a structure factor expressed by a function of interatomic potentials, analytically obtained for the common case and calculated for Fe–Cr solid alloy. We compare the calculation results to experimental data of kinetically analyzed spinodal decomposition process in Fe–Cr alloys obtained by small angle neutron scattering.