Study for material analogs of FeSb${}_2$: material design for thermoelectric materials

Abstract

Using the \emph{ab initio} evolutionary algorithm (implemented in USPEX) and electronic structure calculations we investigate the properties of a new thermoelectric material FeSbAs, which is a material analog of the enigmatic thermoelectric FeSb${}_2$. We utilize the density functional theory and the Gutzwiller method to check the energetics. We find that FeSbAs can be made thermodynamically stable above $\sim$30 GPa. We investigate the electronic structure and thermoelectric properties of FeSbAs based on the density functional theory and compare with those of FeSb${}_2$. Above 50 K, FeSbAs has higher Seebeck coefficients than FeSb${}_2$. Upon doping, the figure of merit becomes larger for FeSbAs than for FeSb${}_2$. Another material analog FeSbP, was also investigated, and found thermodynamically unstable even at very high pressure. Regarding FeSb${}_2$ as a member of a family of compounds (FeSb${}_2$, FeSbAs, and FeSbP) we elucidate what are the chemical handles that control the gaps in this series. We also investigate solubility (As or P for Sb in FeSb${}_2$) we found As to be more soluble. Finally, we study a two-band model for thermoelectric properties and find that the temperature dependent chemical potential and the presence of the ionized impurities are important to explain the extremum in the Seebeck coefficient exhibited in experiments for FeSb${}_2$.

12 pages, 10 figures

References in corpus (9)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• BoltzTraP. A code for calculating band-structure dependent quantities
• Prediction and accelerated laboratory discovery of previously unknown 18-electron ABX compounds
• Magnetism and Charge Dynamics in Iron Pnictides
• Thermopower of correlated semiconductors : application to FeAs2 and FeSb2
• Exotic stable calcium carbides: theory and experiment
• The semiconductor-to-ferromagnetic-metal transition in FeSb2
• Unified picture for the colossal thermopower compound FeSb${}_2$
• Phase stability and large in-plane resistivity in the 112-type iron-based superconductor Ca${}_{1-x}$La${}_x$FeAs${}_2$

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