Static and Dynamical Properties of heavy actinide Monopnictides of Lutetium.

Showkat H Mir,R Ahuja,Prafulla K Jha,Wei Luo,Prakash C Jha,Shweta D Dabhi,M S Islam,Amitava Banerjee

doi:10.1038/srep29309

Abstract

In this work, density functional theory within the framework of generalized gradient approximation has been used to investigate the structural, elastic, mechanical, and phonon properties of lutetium monopnictides in rock-salt crystal structure. The spin orbit coupling and Hubbard-U corrections are included to correctly predict the essential properties of these compounds. The elastic constants, Young’s modulus E, Poisson’s ratio v, shear modulus G, anisotropy factor A and Pugh’s ratio are computed. We found that all lutetium monopnictides are anisotropic and show brittle character. From the wave velocities along [100], [110] and [111] directions, melting temperature of lutetium monopnictides are predicted. Dynamical stability of these monopnictides has been studied by density functional perturbation theory.

Highlights

In recent years, the rare earth (RE) monopnictides and chalcogenides have gained a substantial attention of solid state and material scientists owing to their diverse structural, mechanical, electronic, thermal, and magnetic properties1–3
Our results indicate that all lutetium monopnictides are mechanically stable and elastically anisotropic
The melting temperature calculated is maximum for LuN and was found to decrease as the mass of pnictide ion increases

Summary

Introduction

The rare earth (RE) monopnictides and chalcogenides have gained a substantial attention of solid state and material scientists owing to their diverse structural, mechanical, electronic, thermal, and magnetic properties. RE monopnictides show peculiar magnetic and electronic properties correlated with partially filled f-shell electrons which are delocalised and strongly interact with crystal lattice. RE monopnictides show peculiar magnetic and electronic properties correlated with partially filled f-shell electrons which are delocalised and strongly interact with crystal lattice5 This kind of behaviour have been explained in terms of mixing of f-orbitals with p-orbitals of neighbouring ion and transfer of 4f electrons to 5d conduction band of the rare earth ion. The interaction between f and conduction electrons varies with the interatomic distance and as a consequence the rare earth compounds have peculiar properties as a function of applied hydrostatic pressure. To take into account the effects of strongly correlated f electrons and the exchange and coulomb interactions new methods have been devised One such method is the self-interaction correction (SIC) approach suggested by Gunnarssion and Svane. Afterwards, employing the same scheme, phonon dispersion of these compounds is studied using finite displacement method

Methods

Results

Conclusion