Metastability relationship between two- and three-dimensional crystal structures: A case study of the Cu-based compounds

Abstract

Some of the three-dimensional (3D) crystal structures are constructed by stacking two-dimensional (2D) layers. It remains unclear whether this geometric concept is related to the stability of ordered compounds and whether this can be used to computational materials design. Here, using first principles calculations, we investigate the dynamical stability of copper-based compounds Cu$X$ (a metallic element $X$) in the B${}_h$ and L1${}_1$ structures constructed from the buckled honeycomb (BHC) structure and in the B2 and L1${}_0$ structures constructed from the buckled square (BSQ) structure. We demonstrate that (i) if Cu$X$ in the BHC structure is dynamically stable, those in the B${}_h$ and L1${}_1$ structures are also stable. Although the interrelationship of the metastability between the BSQ and the 3D structures (B2 and L1${}_0$) is not clear, we find that (ii) if Cu$X$ in the B2 (L1${}_0$) structure is dynamically stable, that in the L1${}_0$ (B2) is unstable, analogous to the metastability relationship between the bcc and the fcc structures in elemental metals. The total energy curves for Cu$X$ along the tetragonal and trigonal paths are also investigated.

8 pages, 7 figures

References in corpus (5)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Dynamical stability of two-dimensional metals in the periodic table
• High-throughput computational search for two-dimensional binary compounds: Energetic stability versus synthesizability of three-dimensional counterparts
• Lattice stability of ordered Au-Cu alloys in the warm dense matter regime
• Theory of dynamical stability for two- and three-dimensional Lennard-Jones crystals

Cited by in corpus (1)

• Hypothetical FrAu: An outlier in the B2 compounds