First-principles study of structural, elastic, and thermodynamic properties of ZrHf alloy

Abstract

Structural parameters, elastic constants, and thermodynamic properties of ordered and disordered solid solutions of ZrHf alloys are investigated through first-principles calculations based on density-functional theory (DFT). The special quasi-random structure (SQS) method is used to model the disordered phase as a single unit cell, and two lamella structures are generated to model the ordered alloys. Small strains are applied to the unit cells to measure the elastic behavior and mechanical stability of ZrHf alloys and to obtain the independent elastic constants by the stress–strain relationship. Phonon dispersions and phonon density of states are presented to verify the thermodynamic stability of the considered phases. Our results show that both the ordered and disordered phases of ZrHf alloys are structurally stable. Based on the obtained phonon frequencies, thermodynamic properties, including Gibbs free energy, entropy, and heat capacity, are predicted within the quasi-harmonic approximation. It is verified that there are no obvious differences in energy between ordered and disordered phases over a wide temperature range.

First-principles study of structural, mechanical, and electronic properties of W alloying with Zr

“…Note that the atomic configurations with the lowest energy are selected for subsequent calculations. The lattice parameters of mixed crystals often obey the Vegard's law, [31,32] i.e., the lattice parameter of solid solution is linearly dependent on the concentration of one component and this is valid particularly for substitutional solid solutions. [33] Our calculations for the equilibrium lattice constants of W 1−x Zr x obtained from the total energy as a function of the volume are shown in Fig.…”

Hydrogen evolution reaction between small-sized Zr n (n = 2–5) clusters and water based on density functional theory

“…[9,10] The zirconium atom is a typical of 4d transition metal with an electronic configuration of 4d 2 5s 2 . [11] Metal zirconium and its compounds are frequently utilized as nuclear reactor structural materials, [12][13][14][15][16] refractory materials, [17][18][19][20] and catalyst materials [21][22][23][24] because of their excellent properties. Meanwhile, zirconium and zirconium-based clusters have been widely studied as an excellent hydrogen storage material.…”

The structure and elasticity of phase B silicates under high pressure by first principles simulation

“…under high pressure and temperature. [13][14][15][16][17][18][19][20][21][22][23][24] Differences among the different cases of phase B with different water and Fe content are important for understanding the effects of water and Fe content on mineral properties, the structure and composition of the mantle. Therefore, we investigate the crystal structural and elastic properties of Anhy-PhB, phase B, and Fe-PhB under high pressure by using first-principles calculations.…”