First principles study the stability, mechanical and electronic properties of manganese carbides

The stability, elasticity, hardness and electronic properties of Mn–C binary compounds are investigated by first principles calculations. The lattice parameters, cohesive energy and formation enthalpy of these compounds are calculated and discussed. Furthermore, the elastic constants are calculated by the stress–strain method and satisfy the Born–Huang’s criterion. Meanwhile, the Voigt–Reuss–Hill approximation is applied to estimate the elastic moduli. Besides, the mechanical anisotropy of these compounds is studied by the anisotropic indexes and plotting 3D surface contour of Young’s modulus. A semi-experience method is used to evaluate the hardness of these carbides. Moreover, the sound velocity and Debye temperatures of Mn–C compounds are also discussed.