We present a first-principles study of the phase transition and lattice dynamics of Ce within the framework of the density functional theory using the GGA +U method. Our calculated results denote that under pressure the transition path is a-Ce (fcc)-a 00 -Ce (monoclinic, with two atoms per unit cell
First-principles lattice dynamical study of ScAs and ScSb at zero and high pressure
โ Scribed by Bipul Rakshit; Sankar P. Sanyal; Massimo Celino
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 910 KB
- Volume
- 149
- Category
- Article
- ISSN
- 0038-1098
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โฆ Synopsis
A first-principles pseudopotential method is used to investigate the structural and elastic properties of ScAs and ScSb in their ambient B1(NaCl) and in high pressure B2 (CsCl) phases and phonon structures at zero and close to phase transition pressure. The calculated lattice constants, static bulk modulus, first order pressure derivative of the bulk modulus and the elastic constants are reported in B1 and B2 structures and compared with available experimental and other theoretical results. The phonon properties of these two compounds are compared among themselves which reveal that these compounds are predominantly metallic, due to degeneracy of optical frequencies at the zone centre. At high pressure, near the B1 to B2 transition, the LA mode at X-point softens leading to structural instability.
๐ SIMILAR VOLUMES
An ab initio pseudopotential plane wave method using linear response approach has been employed to study the lattice dynamics of two cubic antiperovskites AsNBa 3 and SbNBa 3 . The bulk properties, elastic constants, phonon dispersion curves, phonon density of states and temperature dependent thermo
Frozen-phonon calculations based on the full-potential linearized augmented-plane-wave method are performed for the X-point phonon modes of the high-pressure FCC phase of solid iodine which becomes a superconductor at T ,-~ 1 K. The longitudinal and the transverse phonon frequencies have been evalua