Mean-field potential approach for thermodynamic properties of lanthanide: Europium as a prototype

In the present paper, a simple conjunction scheme [mean-field potential (MFP) + local pseudopotential] is used to study the thermodynamic properties of divalent lanthanide europium (Eu) at extreme environment. Present study has been carried out due to the fact that divalent nature of Eu arises because of stable half-filled 4f-shell at ambient condition, which has great influence on the thermodynamic properties at extreme environment. Due to such electronic structure, it is different from remaining lanthanides having incomplete 4f-shell. The presently computed results of thermodynamic properties of Eu are in good agreement with the experimental results. Looking to such success, it seems that the concept of MFP approach is successful to account contribution due to nuclear motion to the total Helmholtz free energy at finite temperatures and pressure-induced inter-band transfer of electrons for condensed state of matter. The local pseudopotential is used to evaluate cold energy and hence MFP accounts the s–p–d–f hybridization properly. Looking to the reliability and transferability along with its computational and conceptual simplicity, we would like to extend the present scheme for the study of thermodynamic properties of remaining lanthanides and actinides at extreme environment.

The Theoretical Study of High Pressure Equation of State and Relative Volume Thermal Expansion of fcc Transition Metals Ni, Pd and Pt Using Mean Field Potential Approach

In the theoretical study of thermophysical properties of materials at high temperature and pressure anharmonic effects are important. In this regard, in the present communication, anharmonic effects are taken into account by coupling recently proposed mean field potential (MFP) in conjunction with local pseudopotential for fcc transition metals Ni, Pd and Pt. Using present approach, we have computed volume variation of binding energy at 0K, vibrational free energy of lattice ions (Fion), Helmholtz free energy and relative volume thermal expansion up to melting temperature of Ni, Pd and Pt. Further, applicability of present coupling scheme has been tested by investigating equation of state (EOS) at 300K which explains the microscopic internal structure of material. Our results are in good agreement with experimental and other theoretical findings which demonstrate the capability of present coupling scheme of MFP with local pseudopotential alongwith its computational simplicity.