Crystal structure, magnetism, electronic structure and effect of electron doping in ThCrAsN: An ab-initio study

Abstract

In this work, we use first principles methods, to predict a mechanically and dynamically stable crystal structure of ThCrAsN which is iso-structural to ThXAsN (X = Mn,Fe,Co,Ni). We have investigated its mechanical, thermal, magnetic and electronic properties. Our calculation reveals that the magnetic ground state of ThCrAsN is G-AFM. Bader charge analysis reveals a significant inter-layer charge transfer between ThN and CrAs layers. Electronic structure of ThCrAsN is thoroughly investigated by evaluation of density of states, band structure and FSs for NM as well as G-AFM phases. Our calculation predicts a metallic behaviour for both the phases. Existence of FS pockets, consisting of multiple Cr-d orbitals at different parts of the Brillouin zone is observed. The influence of electron correlation effects on the electronic structure of ThCrAsN has been investigated using the Hubbard model. We also evaluate Lindhard response function to study the FS nesting which indicate a stronger FS nesting along Γ-X direction as compared to the Γ-M direction. Furthermore, we have examined the alterations in the density of states resulting from the partial substitution of Cr atom with Mn atom in ThCrAsN. Our findings suggest the occurrence of a metal-insulator transition in ThCrAsN upon Mn doping.