First-principles study on the effect of pressure on the structure and mechanical properties of Fe2B
Based on the first-principles method of density functional theory,the structure,stability and me-chanical properties of tetragonal Fe2B under pressures of 0～30 GPa were systematically studied.The results show that with the increase of pressure,the calculated lattice parameters gradually decrease,all structures satisfy the thermodynamic stability,the bulk modulus and shear modulus increase gradually,and the toughness is effec-tively improved.The hardness first increases and then decreases,and reaches the maximum value at 18 GPa pressure.The anisotropy increases first and then decreases.The changing trend of Debye temperature is the same as that of Young's modulus.At the same time,the related properties of the phase transition structure—orthorhom-bic phase were also studied.The results show that its structure satisfies the thermodynamic stability but does not satisfy the mechanical stability,so,whether it is stable or not still needs to be studied by subsequent experiments.
First principlesFe2BPressureCrystal structureMechanical properties
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