First-Principle Studies on the Mechanical and Electronic Properties of Al(x)Ni(y)Zr(z) (x = 1~3, y = 1~2, z = 1~6) Alloy under Pressure

The elastic and electronic properties of Al(x)Ni(y)Zr(z) (AlNiZr, Al(2)NiZr(6), AlNi(2)Zr, and Al(5)Ni(2)Zr) under pressure from 0 to 50 GPa have been investigated by using the density function theory (DFT) within the generalized gradient approximation (GGA). The elastic constants C(ij) (GPa), Shear modulus G (GPa), Bulk modulus B (GPa), Poisson’s ratio σ, Young’s modulus E (GPa), and the ratio of G/B have been studied under a pressure scale to 50 GPa. The relationship between Young’s modulus of Al(x)Ni(y)Zr(z) is Al(5)Ni(2)Zr > AlNiZr > Al(2)NiZr(6) > AlNi(2)Zr, which indicates that the relationship between the stiffness of Al(x)Ni(y)Zr(z) is Al(5)Ni(2)Zr > AlNiZr > Al(2)NiZr(6) > AlNi(2)Zr. The conditions are met at 30 and 50 GPa, respectively. What is more, the G/B ratios for AlNiZr, AlNi(2)Zr, Al(2)NiZr(6), and Al(5)Ni(2)Zr classify these materials as brittle under zero pressure, while with the increasing of the pressure the G/B ratios of AlNiZr, AlNi(2)Zr, Al(2)NiZr(6), and Al(5)Ni(2)Zr all become lower, which indicates that the pressure could enhance the brittle properties of these materials. Poisson’s ratio studies show that AlNiZr, AlNi(2)Zr, and Al(2)NiZr(6) are all a central force, while Al(5)Ni(2)Zr is a non-central force pressure scale to 50 GPa. The energy band structure indicates that they are all metal. The relationship between the electrical conductivity of Al(x)Ni(y)Zr(z) is Al(2)NiZr(6) > Al(5)Ni(2)Zr > AlNi(2)Zr > AlNiZr. What is more, compared with Al(5)Ni(2)Zr, AlNi(2)Zr has a smaller electron effective mass and larger atom delocalization. By exploring the elastic and electronic properties, they are all used as a superconducting material. However, Al(5)Ni(2)Zr is the best of them when used as a superconducting material.