A first principle study of electronic band structures and effective mass tensors of thermoelectric materials: PbTe, Mg2Si, FeGa3 and CoSb3

• Published in: Computational materials science Vol. 85; pp. 340 - 346
• Main Authors: Sharma, Sonu, Pandey, Sudhir K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effective mass tensor; Electron density of states and band structure of crystalline solids; Electron states; Electronic structure; Exact sciences and technology; Fermi surface: calculations and measurements; effective mass, g factor; Physics; Thermoelectric materials; Thermoelectric materials; Effective mass tensor; Electronic structure; Band structure; Skutterudite; Iron alloys; Gallium alloys; Lattice parameters; APW calculations; Lead tellurides; Energy gap; Spin-orbit interactions; Density functional method; Effective mass; Magnesium silicide; Cobalt antimonides; Exchange interactions; Bulk modulus; Transition element alloys
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2014.01.011

•We have studied the electronic structures of the four thermoelectric materials.•The recently developed PBEsol exchange correlation functional has been employed.•The lattice parameters and bulk moduli are closer to the experimental values.•The influence of SOC on the electronic structure has also been studied.•The effective mass of these compounds is also computed. The state-of-the-art full-potential linearized augmented-plane wave methods have been employed to study the electronic structures of four thermoelectric materials PbTe, Mg2Si, FeGa3 and CoSb3 belonging to chalcogenide, silicide, correlated systems and skutterudite group, respectively. Here we used the PBEsol exchange correlation functional, which predicts lattice parameters very close to the experimental values. The calculated bulk moduli are also found to be in fairly good agreement with the experimental ones. In comparison to the experimental values this functional underestimates the band gap of Mg2Si and CoSb3; and overestimates the band gap of PbTe and FeGa3. The effect of spin–orbit coupling (SOC) on the electronic structures of these compounds is also studied in detail. There is a drastic decrement (∼90%) of band gap of PbTe in the presence of SOC whereas for rest of the compounds this decrement is within 17%. The effective mass tensors are calculated for those bands which are expected to influence the transport behaviour of the compounds.