Investigating the effect of electronic correlation on transport properties and phononic states of Vanadium

TL;DR

This study investigates how electronic correlations influence the transport properties and phononic states of Vanadium, revealing that electron-electron interactions are negligible for transport but significantly affect thermoelectric and phononic characteristics.

Contribution

It provides a comparative analysis of DFT and DFT+DMFT approaches, highlighting the importance of electronic correlations on thermoelectric and phononic properties of Vanadium.

Findings

Electron-electron interactions have negligible impact on electrical resistivity and thermal conductivity.

DFT+DMFT results for Seebeck coefficient align well with experimental data.

Phononic states at DFT+DMFT differ significantly from DFT, matching experimental phonon energies more closely.

Abstract

In the present work, we have tried to investigate the importance of electronic correlation on transport properties and phononic states of Vanadium (V). The temperature-dependent electrical resistivity ($\rho$) and electronic part of thermal conductivity ($\kappa_e$) due to electron-electron interactions (EEIs) and electron-phonon interactions (EPIs) are computed. The values of $\rho$ due to EEIs are found to be extremely small in comparison to $\rho$ due to EPIs. For instance, at 300 K, the calculated value of $\rho$ due to EEIs (EPIs) is $\sim$ 0.859$\times10^{-3}$ ($\sim$ 0.20) $\mu\Omega$m. The magnitudes of $\kappa_e$ due to EPIs are found to be in good agreement with the experimental results. These observations indicate the negligible importance of EEIs to these quantities for V. However, at 300 K, the value of Seebeck coefficient ($S$) at DFT+DMFT level ($\sim$ -0.547 $\mu$VK$^{-1}$) is found to be entirely different than at DFT level ($\sim 7.401$ $\mu$VK$^{-1}$). Also, the DFT+DMFT value of $S$ at 300 K is in good match with the available experimental data (-1.06 $\mu$VK$^{-1}$, 1.0 $\mu$VK$^{-1}$). Apart from this, the study of phononic states at DFT and DFT+DMFT level is performed. The obtained phononic band structure and phonon DOS at DFT+DMFT differ to a good extent from that at DFT. The maximum energy of phononic state obtained at DFT (DFT+DMFT) is $\sim$ 33.83 ($\sim$ 35.15) meV, where the result of DFT+DMFT is obtained more closer to the experimental data (35.15, 36.98 & 41.77 meV). These results highlight the importance of electronic correlation on $S$ & phononic states of simple correlated V metal.