The First Principle Of The Mechanical And Electronic Properties Of The Transition Metal Compounds Mo ₂ BC And Mo ₃ Al ₂ C

We employ ab initio plane-wave pseudo potential density functional theory to study the mechanical and electronic properties of the cubic Mo3Al2C and the orthorhombic Mo2BC. The main results are listed as follows:1.The results show that the orthorhombic structure of Mo2BC are stable at zero pressure, and the optimized equilibrium lattice parameters are in good agreement with the experimental data. For the orthorhombic structure of Mo2BC, the obtained bulk, shear and Young’s modulus are 308,187 and 471 GPa respectively. Poission’s ratio calculated is 0.245, and Debye temperature is 80 K. The bondings of Mo2BC are of the mixture of covalent and ionic bondings by the electron structures, and exhibit some metallic.2.The results show that the cubic Mo3Al2C is stable under pressures of 0-50 GPa, the bulk modulus, shear modulus, Young’modulus and incompressi bility is intensified with the increase of the pressure, but the lattice paramete rs and volume are decreased. B/G=2.26 shows that Mo3Al2C is ductile materi al. The bondings of Mo3Al2C are of the mixture of covalent, metal and ionic bondings. Mo3Al2C exhibits metallic.