The structural, thermodynamical, elastic, and vibrational properties of LaBi

Abstract

In this study, we have studied the structural, elastic, electronic, thermodynamical, and vibrational properties of LaBi by performing ab initio calculations within the local-density approximation (LDA). In particular, the lattice constant, bulk modulus, cohesive energy, phase transition pressure (P t ) from the NaCl (B1) to the CsCl (B2) structure, second-order elastic constants (C i j ), electronic band structures, and lattice dynamical properties were calculated and compared with the available experimental and other theoretical values. In order to obtain further information, we have also predicted Young's modulus (E), Poisson's ratio (ν), the anisotropy factor (A), sound velocities, Debye temperature (θ D ), and their pressure-dependent behaviour in the B1 phase. In addition, we have estimated the temperature-dependent behaviour of some thermodynamical properties, such as entropy and heat capacity from the lattice dynamical data.

Structural analysis of partially covalent lanthanide and actinide bismuthides with phase‐transition pressures below 14 GPa

“…Our present values of SOECs are close to available theoretical data [15][16][17]. The pressure derivatives of bulk modulus have been compared with theoretical [25] and experimental data [5,22].…”

“…The pressure derivatives of bulk modulus have been compared with theoretical [25] and experimental data [5,22]. Due to lack of experimental data for SOECs, we have compared our results with theoretical data and we found that the values of SOECs are of the same order as reported by others [15][16][17]. To the best of our knowledge no experimental data of second-order elastic constants for these rare-earth pnictides have been reported as yet.…”

“…The solid lines represent the present work and the solid squares, solid triangles and solid circles represent the ab-initio calculation performed by Ciftci et al [15]. It is clear from this figure that in the case of LaBi, it is found that C 11 varies largely under the effect of pressure as compared with the variations in the C 12 and C 44 .…”

“…We have calculated the second-order elastic constants (SOECs) with pressure for the present compounds. We have compared our results in the 0-25 GPa pressure range for LaBi with ab-initio calculation by Ciftci et al [15] in Fig. 10.…”

“…C 11 (Others) [15] C 12 (Others) [15] C 44 (Others) [15] Elastic properties Pressure (GPa) Figure 10 Variation of second-order elastic constants (SOECs) with pressure for LaBi. The solid lines represent the present work and the symbols represent the ab-initio calculation by Ciftci et al [15].…”