Mechanical properties and variation in SOC going from La to Nd in intermetallic RIn3 and RSn3 (R = La, Ce, Pr, Nd)

Abstract

First principle studies of the cubic rare-earth intermetallics RIn₃ and RSn₃ (R = La, Ce, Pr, Nd) have been carried out within the framework of density functional theory using the full potential linearized augmented plane waves plus local orbital method (FP-LAPW + lo). The calculated structural parameters with different functionals are found to be consistent with the experimental results. The effect of the Hubbard potential on the density of states is discussed in detail. It is observed that the inclusion of spin–orbit coupling (SOC) causes degeneracies of the electronic band structures in the vicinity of the Fermi level of these compounds. Furthermore, the SOC effect enhances as one goes from La to Nd in a compound, which demonstrates the interesting nature of this effect in the periodic table. The elastic constants, bulk moduli, shear moduli, Young’s moduli, anisotropy, Kleinman parameters, Poisson’s ratios, sound velocities for shear and longitudinal waves, and Debye temperatures are calculated and discussed, which reveal that these compounds are ductile in nature.