Heat Capacity Analysis and First-Principles Calculations of Structural and Magnetic Properties of Mn5Si3 Compound

The paper presents a comprehensive study of the heat capacity as well as structural and magnetic properties of the Mn5Si3 compound specimen. As part of the application of the combined Sommerfeld–Debye model to experimental heat capacity curves, the Debye temperature ΘD = 391.8 ± 2.3 K with an electron heat capacity coefficient γ = 12.3 ± 0.1 mJ mol–1 K–2 has been determined. According to calculations of the density functional theory, the ground state of the Mn5Si3 compound is the hexagonal P63/mcm structure ordered ferromagnetically. It has been revealed that the best agreement of the theoretically calculated behavior of the heat capacity Cph with experimental measurements is observed for the orthorhombic structure of Pmma symmetry in the AFM ordering.