We predict two novel group 14 element alloys Si_(2)Ge and SiGe_(2) in P6_(2)22 phase in this work through first-principles calculations.The structures,stability,elastic anisotropy,electronic and thermodynamic properti...We predict two novel group 14 element alloys Si_(2)Ge and SiGe_(2) in P6_(2)22 phase in this work through first-principles calculations.The structures,stability,elastic anisotropy,electronic and thermodynamic properties of these two proposed alloys are investigated systematically.The proposed P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2) have a hexagonal symmetry structure,and the phonon dispersion spectra and elastic constants indicate that these two alloys are dynamically and mechanically stable at ambient pressure.The elastic anisotropy properties of P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2) are examined elaborately by illustrating the surface constructions of Young’s modulus,the contour surfaces of shear modulus,and the directional dependence of Poisson’s ratio;the differences with their corresponding group 14 element allotropes P6_(2)22-Si_(3) and P6_(2)22-Ge_(3) are also discussed and compared.Moreover,the Debye temperature and sound velocities are analyzed to study the thermodynamic properties of the proposed P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2).展开更多
基金supported by the National Natural Science Foundation of China(No.61804120)the Scientific Research Program of Shaanxi Provincial Education Department(19JK0471)the Science and Technology Foundation for Youths of Xi’an University of Architecture and Technology(QN1625)。
文摘We predict two novel group 14 element alloys Si_(2)Ge and SiGe_(2) in P6_(2)22 phase in this work through first-principles calculations.The structures,stability,elastic anisotropy,electronic and thermodynamic properties of these two proposed alloys are investigated systematically.The proposed P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2) have a hexagonal symmetry structure,and the phonon dispersion spectra and elastic constants indicate that these two alloys are dynamically and mechanically stable at ambient pressure.The elastic anisotropy properties of P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2) are examined elaborately by illustrating the surface constructions of Young’s modulus,the contour surfaces of shear modulus,and the directional dependence of Poisson’s ratio;the differences with their corresponding group 14 element allotropes P6_(2)22-Si_(3) and P6_(2)22-Ge_(3) are also discussed and compared.Moreover,the Debye temperature and sound velocities are analyzed to study the thermodynamic properties of the proposed P6_(2)22-Si_(2)Ge and P6_(2)22-SiGe_(2).
