First-principles study of structural and electronic properties of Laves phases structures YM2(M = Cu and Zn)

M.K Benabadji,H.I Faraoun,A El Bouari,I Mansouri,R El Ouatib,H Hannache,R Moussa,A Aboulayt,M Lamire,S Krimi

doi:10.1051/matecconf/20130504037

Abstract

First-principles calculations have been carried out to investigate the structural properties and electronic structure of the main binary Laves phase YCu2 and YZn2 with C14, C14, C36 and CeCu2 structures in Cu-Y-Zn alloy, respectively. The total energies of Laves phases with various occupations of nonequivalent lattice sites in all four structural forms have been calculated Ab initio by a pseudopotential VASP code. The optimized structural parameters were in very good agreement with the experimental values. The calculated heat of formation showed that the CeCu2-YCu2 and YZn2 Laves phase was of the strongest alloying ability and structural stability. The electronic density of states (DOS) and charge density distribution were given.

Highlights

This paper concentrates on a particular class of intermetallic phases, the so-called Laves phases
Calculations were performed using the Vienna ab initio simulation package (VASP) [12,13,14] code based on the density functional theory (DFT) [15, 16]
Sampling of the Brillouin zone was done via 9 × 9 × 9 and 11 × 11 × 11 k-point grid generated according to the Monkhorst–Pack scheme [19] for YCu2 and YZn2 respectively

Summary

INTRODUCTION

This paper concentrates on a particular class of intermetallic phases, the so-called Laves phases. An intermetallic compound is classified as a Laves phase purely on the basis of the geometry of the crystal structure. In particular geometrical concepts relying on symmetry, packing density or electronic factors like valence electron concentration or the difference in electronegativity have been considered. First-principles density functional theory calculations have been broadly used to study the electronic structure and mechanical properties of laves phase compound. We have performed ab initio calculations to investigate the stability, electronic and structural properties of YCu2 and YZn2

CALCULATION METHODS AND CRYSTAL STRUCTURES

Stability and structural properties

Enthalpy of formation

Densities of States

Charge densities distribution

SUMMARY AND CONCLUSION