Structural, electronic properties and Fermi surface of ThCr2Si2-type charge-balanced KFe2AsSe phase as a parent system for a new group of "mixed" pnictide-chalcogenide superconductors

TL;DR

This study investigates the structural and electronic properties of KFe2AsSe, a proposed parent compound for a new class of Fe-based superconductors that bridges existing pnictide and chalcogenide families.

Contribution

It introduces KFe2AsSe as a charge-balanced intermediate system and analyzes its properties using first-principles calculations.

Findings

KFe2AsSe has a stable crystal structure.

Electronic band structure suggests potential for superconductivity.

Fermi surface features indicate similarities to known Fe-based superconductors.

Abstract

The ThCr2Si2-type arsenide-selenide phase KFe2AsSe is proposed as a parent system for a new "intermediate" group of Fe-based superconducting materials bridging the known families of Fe-pnictides (such as BaFe2As2) and Fe-chalcogenides (such as KxFe2-ySe2) superconductors. The characterization of the proposed charge-balanced phase by means of FLAPW-GGA approach covers the crystal structure, As/Se atomic ordering, stability, electronic bands, Fermi surface, and density of electronic states.