New ternary superconducting compound LaRu ₂ As ₂ : Physical properties from density functional theory calculations

Abstract

In this paper, we have presented the density functional theory (DFT) based calculations performed within the first-principles pseudopotential method to investigate the physical properties of the newly discovered superconductor LaRu 2 As 2 for the first time. The optimized structural parameters are in good agreement with the experimental results. The calculated independent elastic constants ensure the mechanical stability of the compound. The calculated Cauchy pressure, Pugh's ratio as well as Poisson's ratio indicate that LaRu 2 As 2 should behave as a ductile material. Due to low Debye temperature, LaRu 2 As 2 may be used as a thermal barrier coating (TBC) material. The new compound should exhibit metallic nature as its valence bands overlap considerably with the conduction bands. LaRu 2 As 2 is expected to be a soft material and easily machineable because of its low hardness value of 6.8 GPa. The multi-band nature is observed in calculated Fermi surface. A highly anisotropic combination of ionic, covalent, and metallic interactions is expected in accordance with charge density calculations.

Effect of Pressure on the Superconducting Transition Temperature and Physical Properties of CaPd2P2: A DFT Investigation

“…When the temperature of the solid is higher than θ D (i.e., T > θ D ), the vibration mode is considered to have k B T energy and in the case of T < θ D , the vibration mode is expected to be at rest. 65 The low-temperature vibration is a result of acoustic vibration. The θ D is related to different thermodynamic parameters such as the thermal expansion of solids, phonons, thermal conductivity, specific heat, and melting point.…”

Insights into the physical properties of a new 211 MAX phase Nb2CuC

“…The elastic constants C ij are calculated using finite-strain theory [22] as implemented in the CASTEP code. This method is widely used for all kind of crystals [23][24][25][26][27][28][29][30][31][32][33][34][35]. According to this theory, a given set of identical deformations (strains) is applied to the conventional unit cell, accepting the relaxation of the atomic degrees of freedom.…”

First-principles study of the electronic structure of CaKRu$_4$P$_4$

“…Due to the bands shift, there are two more hole-type Fermi surface sheets, of which one is centered around Γ-Z while the other one forms a pocket around X. The electronic structure of CaKRu 4 P 4 under pressure is very similar to that of 122-type Ru-based superconductors LaRu 2 P 2 and LaRu 2 As 2 [44][45][46][47] . Therefore, CaKRu 4 P 4 has a large potential to show superconductivity as a phonon-mediated medium coupled BCS superconductors.…”

“…Since the element Ru locates in the same group as the element Fe in the periodic table, the similar physical properties are expected in the Ru-based and Fe-based compounds. There have been a number of studies focused on the Ru-related superconductors to date [40][41][42] 41,42,[44][45][46][47] . Furthermore, topological states, including both type-I and type-II Dirac fermions, can be created and regulated with pressure in this material.…”