First-principle study of the structural, mechanical, electronic and thermodynamic properties of intermetallic compounds: Pd₃M (M=Sc, Y)

Abstract

The mechanical, electronic and thermodynamic properties of Pd3M (M[Formula: see text]=[Formula: see text]Sc, Y) compounds have been investigated using the Full Potential Linearized Augmented Plane Wave (FP-LAPW) formalism. The generalized gradient approximation (GGA) is used to treat the exchange–correlation terms. The calculated formation enthalpies and the cohesive energies reveal that the L12 structure is more stable than the D0[Formula: see text] one. The obtained lattice parameters and bulk modulus calculations conform well to the available experimental and theoretical results. The elastic and mechanical properties are analyzed and results show that both compounds are ductile in nature. The Debye temperature and melting temperature are also estimated and are in a good agreement with experimental findings. The total and partial densities of states are determined for L12 and D0[Formula: see text] structures. The density of states at the Fermi level, [Formula: see text]([Formula: see text]), indicates electronic stability for both compounds. The presence of the pseudo-gap near the Fermi level is suggestive of formation of directional covalent bonding. The number of bonding electrons per atom [Formula: see text] and the electronic specific heat coefficient [Formula: see text] are also determined. The quasi-harmonic Debye model has been used to explore the temperature and pressure effects on the thermodynamic properties for both compounds.

Effect of La-concentration (x) on some physical properties of LaxSm1-xS (x = 0, 0.1, 0.25 and 0.35) alloys

“…The requirement of mechanical stability in a cubic crystal leads to the following restrictions on the elastic constants, (C11 -C12) > 0, C11> 0, C44> 0, (C11 + 2C12) > 0 [29][30][31][32]. The elastic constants Cij in table 2 of Schärerand Wachter [3] obey these stability conditions.…”

Directional dependency of mechanical properties in gallium phosphide semiconducting material

“…If the second-order elastic stiffness constants Cij and the mass density ρ of the crystal areknown, it is possible to predict the acoustic sound velocities and the Debye temperature θD of materials [36,37]. Many researchers have extensively employed ab initio methods to investigate the elastic constants Cij and structural, electronic and piezoelectric properties of materials [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54]. Bioud [54] has used the elastic constants Cij to calculate the wave velocities andthe Debye temperature of CuX (X = Cl, Br) binary compounds Blackman's [55] proposed a formula which is usually used to predict the θD of a material from its elastic constants Cij.…”

Effect of Solute Ce on Mechanical Properties and Electronic Structure of <i>γ</i>-Fe: Insights from a First-principles Study

“…A negative value of formation enthalpy indicates that it is conducive to the formation of a stable Fe-Ce-M system, and with smaller formation enthalpies, the system is stronger. 21) From Fig. 2(b), the formation enthalpy of Fe-Ce system is negative ( − 1.94 eV), so it can be judged that, in theory, Ce can be solubilized in γ -Fe.…”