High Pressure Thermoelasticity of Body-centered Cubic Tantalum

Abstract

We have investigated the thermoelasticity of body-centered cubic (bcc) tantalum from first principles by using the linearized augmented plane wave (LAPW) and mixed--basis pseudopotential methods for pressures up to 400 GPa and temperatures up to 10000 K. Electronic excitation contributions to the free energy were included from the band structures, and phonon contributions were included using the particle-in-a-cell (PIC) model. The computed elastic constants agree well with available ultrasonic and diamond anvil cell data at low pressures, and shock data at high pressures. The shear modulus $c_{44}$ and the anisotropy change behavior with increasing pressure around 150 GPa because of an electronic topological transition. We find that the main contribution of temperature to the elastic constants is from the thermal expansivity. The PIC model in conjunction with fast self-consistent techniques is shown to be a tractable approach to studying thermoelasticity.

To be appear in Physical Review B

Cited by in corpus (13)

• Thermal properties of materials from ab-initio quasi-harmonic phonons
• Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell
• First-principles thermal equation of state and thermoelasticity of hcp Fe at high pressures
• First-principles thermoelasticity of bcc iron under pressure
• Elastic isotropy of hcp-Fe under Earth core conditions
• The particle-in-cell model for ab initio thermodynamics: implications for the elastic anisotropy of the Earth's inner core
• Sound velocity measurements of tantalum under shock compression in the 10-110 GPa range
• Enhanced magnon spin transport in NiFe${}_2$O${}_4$ thin films on a lattice-matched substrate
• Comment on "On the importance of the free energy for elasticity under pressure"
• Thermal effects on lattice strain in hcp Fe under pressure
• The temperature-dependent elastic properties of B2-MgRE intermetallic compounds from first principles
• Nonlinear elasticity of prestressed single crystals at high pressure and various elastic moduli
• Calculation of elastic constants of embedded-atom-model potentials in the NVT ensamble