Interstitial disorder in iron-based superconductor: A first-principles study

Abstract

FeSe in bulk, film or layer form as well as its alloys have shown many intriguing magnetic and superconducting properties. In this paper, we examine the role of interstitial disorder in changing the various electronic, magnetic and superconducting properties of FeSe using ab-initio method. We have studied the electronic properties of FeSe doped interstitially with the transition metal (TM) impurities, Fe(TM) x Se (where TM ≡ V, Mn, Co, Ni, and x = 0.0, 0.01, 0.04 and 0.10). Our results, analyzed in terms of density of states (DOS), band structure, Fermi surface (FS), and local and total magnetic moments, show that the excess of the transition-metal atoms substantially modify the Fermi surface of FeSe. We have also estimated the value of the electron-phonon mass enhancement factor, the Hopfield parameter and the superconducting transition temperature for these alloys.