The study of physical properties of intermetallic compounds, especially under extreme conditions such as high pressure, is of considerable interest from both fundamental and applied points of view. In particular, the Al7Cu2Fe alloy, which exhibits complex phase transitions and unique structural characteristics, attracts the attention of researchers. This paper analyzes the effect of hydrostatic pressure on the physical properties and Debye temperature of this alloy using first-principles calculations within the framework of density functional theory (DFT).
The calculation method is based on the VASP (Vienna Ab initio Simulation Package) software package using PAW (Projector Augmented Wave) pseudopotentials and the GGA (Generalized Gradient Approximation) exchange-correlation functional in the PBE (Perdew-Burke-Ernzerhof) parameterization. The calculations were performed for a bulk unit cell of Al7Cu2Fe at different pressure values in the range from 0 to 50 GPa with a step of 5 GPa. For each pressure value, a complete optimization of the structure was performed in order to minimize the energy.
In this paper, the effects of different pressure levels on the lattice parameters, mechanical properties, electronic properties and Debye temperature of AlCu2Fe alloy are investigated using first-principles calculations. The calculated lattice parameters at normal pressure (0 GPa) show good agreement with previously published research results.
Using the density of states analysis and computational methods (in particular, the calculation of the enthalpy of formation and elastic moduli), the mechanical stability of the alloy was confirmed. It was found that the parameters B, G, E, ΘD and H show a proportional increase with increasing applied pressure. The analysis of the B/G ratio indicates a transition of the material to a plastic state at a pressure of 30 GPa, which indicates a positive effect of pressure on improving the plastic properties of the material.
The obtained results demonstrate a nonlinear change in the volume of the unit cell with increasing pressure, which indicates high compressibility of the alloy. The calculated values of the bulk modulus show a tendency to increase with increasing pressure, which reflects the growth of deformation resistance. Based on the obtained data, the values of the Debye temperature, which characterizes the vibrational properties of the lattice, were calculated. It is shown that the Debye temperature monotonically increases with increasing pressure, which is associated with an increase in the rigidity of interatomic bonds.
The obtained results allow us to better understand the behavior of the Al7Cu2Fe alloy under high pressure conditions and can be used to develop new materials with specified properties. Further research will be aimed at studying the influence of other factors, such as temperature and structural defects, on the physical properties of this alloy.
Author: Jinzhong Tian, Yuhong Zhao, Zhiqin Wen, Hua Hou,Peide Han
Institute: College of Materials Science and Engineering, North University of China, Taiyuan 030051, P.R. China, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, People’s Republic of China