Electronic, magnetic, elastic and thermodynamic properties of antiperovskite metallic compounds Mn3XN (X = Ni, Pd, Pt): A DFT study

Antiperovskite compounds have been attracting a lot of attention because of their unique and remarkable properties. Although antiperovskite metallic compounds Mn 3 XN (X = Ni, Pd, Pt) have been successfully prepared as potential magnetic materials, the structural, electronic, elastic and thermodynamic properties are still unclear. So, in this work, we apply the first-principles calculations to investigate the physical properties of Mn 3 XN. The results of formation enthalpy show that Mn 3 XN compounds are thermodynamically stable and follow the order of Mn 3 NiN > Mn 3 PdN > Mn 3 PtN. The results of band structure and density of states prove that all Mn 3 XN compounds are magnetic metals and the magnetism of Mn 3 XN comes mainly from the contribution of Mn atoms. The calculated bulk modulus and shear modulus of Mn 3 PtN are bigger than the Mn 3 PdN and Mn 3 NiN. Especially, we give the three-dimensional Young's modulus surface and the projection surface on different planes for three compounds. With respect to the anisotropic characteristics, Mn 3 PdN may be a potentially isotropic material and Mn 3 NiN has the most obvious anisotropy. The sound velocities of the three compounds in different directions are calculated to obtain the Debye temperature. The Debye temperatures of Mn 3 NiN, Mn 3 PdN, Mn 3 PtN are calculated to be 445 K, 423 K and 408 K, respectively. Importantly, the Debye temperature increases with the increasing of pressure and the decreasing of temperature. Finally, we give the critical pressure and charge density difference of three compounds. • The physical properties of the Mn 3 XN (X = Ni, Pd, Pt) compounds are studied by using first-principles calculations. . • The magnetic moments of Mn 3 XN (X = Ni, Pd, Pt) compounds are discussed. • Using the magnetic transition, the critical pressures of Mn 3 XN (X = Ni, Pd, Pt) compounds are investigated. • The Debye temperatures of Mn 3 XN (X = Ni, Pd, Pt) compounds are evaluated under different temperature and pressure. • Bonding characteristics of Mn 3 XN (X = Ni, Pd, Pt) compounds are revealed by charge density difference.