The electronic and elasticity properties of new half-metallic chalcogenides Cu₃TMCh₄ (TM = Cr, Fe and Ch = S, Se, Te): an ab initio study

ABSTRACT

The ternary copper-based chalcogenides Cu₃TMCh₄ (TM = Cr, Fe and Ch = S, Se, Te), which have simple cubic (SC) crystal structure and conform to $P\overline{4}3m$ space group with 215 space number, have been investigated by spin-polarised generalised gradient approximation (GGA) in the framework of density functional theory (DFT). All systems have been considered in ferromagnetic (FM) order. The mechanical and thermal properties and the electronic band structures of these systems have been investigated after the well-optimised structural parameters have been obtained. The spin-polarised electronic band structures of all the systems exhibit half-metallic behaviour with band gaps in minority spin channel from 0.29 eV for Cu₃FeTe₄ to 1.08 eV for Cu₃CrS₄, while metallic band structures are observed for majority spins. This agrees with the calculated total magnetic moments which are close to integer values. The calculated negative formation enthalpies indicate the energetic and thermodynamic stability of these compounds. Moreover, the calculated elastic constants verify that these materials are stable mechanically due to satisfying Born stability criteria. The estimated anisotropy shear factors show that Cu₃FeS₄, Cu₃FeSe₄ and Cu₃CrSe₄ systems have nearly isotropic character with 1.004, 0.910, and 0.958 values, respectively, whereas other compounds have relatively low anisotropic behaviour.

KEYWORDS:

• Half-metallic
• electronic structure of bulk materials
• mechanical properties of solids
• density functional theory
• chalcogenides

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported in part by TÜBİTAK (The Scientific & Technological Research Council of Turkey) through TR-Grid e-Infrastructure Project, part of the calculations have been carried out at ULAKBİM Computer Center.