Exploring the structural, electronic, magnetic, mechanical, thermodynamic, and optical behavior of Mn2TaS Full-Heusler alloy via first-principles calculations

DFT calculations reveal that the Heusler alloy Mn₂TaS is structurally stable in both normal (5.84 Å) and reverse (6.05 Å) phases. Both exhibit metallic behavior with notable spin polarization (52 % and 40 %), indicating strong potential for spintronic applications. Magnetic analysis shows that the inverse phase stabilizes in a ferromagnetic ground state, exhibiting total magnetic moments of 4.96 μB (GGA) and 5.39 μB (GGA + U). In contrast, the normal phase approaches almost compensated magnetism under GGA and SCAN, but exhibits ferromagnetism with a moment of 3.39 μB under GGA + U. Mechanical stability is confirmed by elastic constants, with bulk and Young's moduli of 118.66 GPa and 208.61 GPa, indicating high compressive strength and stiffness. Thermodynamic and dynamic stability are confirmed by heat capacity, entropy and phonon analysis. Optical calculations show strong UV absorption and notable IR response, highlighting Mn₂TaS for UV and IR device applications.