Novel Laves phase superconductor NbBe 2 : A theoretical investigation

Abstract

A new Laves phase superconductor NbBe 2 , prototype with MgCu 2 , having maximum T c ~2.6 K has been reported very recently. Based on first-principle calculations, we systematically study the structural, elastic, mechanical, electronic, thermal and superconducting properties of the newly reported superconducting intermetallic compound NbBe 2 . The study of Cauchy pressure and Pugh's ratio reveal the brittle manner of NbBe 2 . This compound exhibits metallic conductivity and the Nb-Be bonds have a covalent feature in which the contribution of Nb-4d state is dominant near Fermi level. The Debye temperature of NbBe 2 is 664.54 K calculated using our elastic constants data. We obtain the heat capacity (C v ) of NbBe 2 at ambient condition is 20.75 cal/cell K using quasi-harmonic model. Finally, we investigate the electronphonon coupling constant, phonon dispersion curve and density of states which indicates that the compound under study is a weakly coupled BCS superconductor.

Investigation of the physical properties of two Laves phase compounds HRh2 (H = Ca and La): A DFT study

“…For metallic compounds the value of Cauchy pressure is positive and for nonmetallic compounds the value of the Cauchy pressure is negative [33]. As shown in Table 2 both of compounds have positive value of Cauchy pressure indicating that both 6 compounds have metallic behaviors. This result is completely satisfying the result having from the analysis of electronic band structures of these compounds discussed in section C. to 0.5 implies the force exists in a solid is central [35].…”

“…227) and their equilibrium lattice parameters are 7.52 Å and 7.64 Å respectively [12,14]. The atomic positions of H (H = Ca and La) and Rh in the unit cell are (0, 0, 0) and (0.625, 0.625, 0.625) respectively [6]. Both the compounds have eight formula units in the unit cell.…”

“…The clear understanding of different superconducting system is still challenge in the field of condensed matter physics. The cubic laves phase compounds are easy to study because of their simple structure and chemical composition [6,7]. Smith et al [8] who first investigated the electronic properties and thermal expansion character of hexagonal laves phase CaMg 2 and cubic laves phase MgCu 2 .…”

The physical properties of ThCr2Si2- type nickel-based superconductors BaNi2T2 (T = P, As): An ab-initio study

“…This analysis reveals that both the phases under study show metallic feature. The metallic behaviors of BaNi 2 P 2 and BaNi 2 As 2 offer a hint that these compounds may be superconductor [46]. The partial and total density of states for the primitive cell of BaNi 2 T 2 (T= P, As) are displayed in Fig.…”

Superconductivity at ∼0.049 K in Laves Phase HfZn2 Predicted by First Principles

“…The Laves phase compounds are considered as promising candidates for superconductivity with widely varying transition temperatures [1]. The study of this compound is so much attractive due to their large differences in transition temperature in the same crystal classes and simple crystal structure.…”