Thermal conductivity and diffusion-mediated localization in Fe(1-x)Cr(x) alloys from first principles

TitleThermal conductivity and diffusion-mediated localization in Fe(1-x)Cr(x) alloys from first principles
Publication TypeJournal Article
Year of Publication2011
AuthorsAlam A, Chouhan RK, Mookerjee A
Journal TitlePhysical Review B
Volume84
Pages224309
Date Published12
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000298556700006
KeywordsAMORPHOUS-SILICON
Abstract

We apply a Kubo-Greenwood-type formula combined with a generalized Feynman diagrammatic technique to report a first-principles calculation of the thermal transport properties of disordered Fe(1-x)Cr(x) alloys. The diagrammatic approach simplifies the inclusion of disorder-induced scattering effects on the two-particle correlation functions and hence renormalizes the heat current operator to calculate configuration averaged lattice thermal conductivity and diffusivity. The thermal conductivity kappa(T) in the present case shows an approximate quadratic T dependence in the low-temperature regime (T < 20 K), which subsequently rises smoothly to a T-independent saturated value at high T. A numerical estimate of mobility edge from the thermal diffusivity data yields the fraction of localized states. It is concluded that the complex disorder scattering processes, in force-constant dominated disorder alloys such as Fe-Cr, tend to localize the vibrational modes quite significantly.

DOI10.1103/PhysRevB.84.224309
Alternate JournalPhys. Rev. B