Temperature-dependent properties of magnetic CuFeS2 from first-principles calculations: Structure, mechanics, and thermodynamics

Abstract

Chalcopyrite (CuFeS2) is an antiferromagnetic semiconductor with promising magnetic and electrical properties, although these properties are not yet completely understood. The structural, magnetic, and electronic properties of bulk CuFeS2 were studied via first-principles plane-wave pseudopotential calculations based on density functional theory (DFT) using DFT+U and hybrid functional B3LYP methodology. The temperature-dependent structural, thermal, and mechanical properties of tetragonal CuFeS2 were also investigated via density functional perturbation theory. Furthermore, the structural parameters, elastic constants, bulk and shear moduli, volume expansion, and specific heats as a function of temperature were evaluated. Tetragonal CuFeS2 was found to exhibit negative thermal expansion behavior at temperatures lower than 100 K. A comprehensive comparison of the various calculated parameters with earlier published studies is also presented along with available experimental data and used as a basis to critically discuss the various properties of CuFeS2.