Abstract
By means of density functional theory (DFT) calculations, we have systematically investigated the effect of hydrostatic pressure on the structural, electronic and elastic properties of barium-doped silicon clathrate Ba8Si46 in the type-VIII structure (α phase). Physical properties are calculated under different conditions of pressure (0 GPa to 45 GPa) using the GGA-PBE functional. Those calculations have been performed using the Cambridge serial total energy package CASTEP within the Materials Studio package. Electronic properties have shown that type-VIII Ba8Si46 has metal-like properties with a fundamental bandgap of 1 eV. Under pressure the fundamental bandgap increases slightly and the positions of the valence band maximum VBM and the conduction band minimum CBM remain unchanged when pressure is changed from 0 to 25 GPa, but when pressure is set to 30 GPa the CBM is transited from its initial position (Γ-H segment) towards the Γ(0,0,0) point, this indicates that the bandgap nature of this material can be tuned through strain engineering. We found that the compound is mechanically stable under the pressure range and might be unstable or collapse when pressure exceeds 44 GPa. These findings need to be confirmed experimentally through synthesis, a comparison with the type-I and the guest-free counterparts has exhibited promising features for the type-VIII Ba8Si46.
Highlights
The quest for a perfect semiconductor that combines several features is a challenging task and a revived competitive scientific topic for materials scientists and engineers
First-principles calculations in the frame of the density functional theory (DFT) within the GGA approach are employed to investigate the main structural features and the impact of hydrostatic pressure on the structural, electronic and elastic properties of type-VIII Ba8Si46 silicon clathrates, this paper is organized as follows: the first section outlines the theoretical approach including our computational details and structural aspects of the clathrate, the second section discusses the electronic properties under pressure, and the elastic properties under pressure are discussed in detail
In order to investigate the effect of hydrostatic pressure on the physical properties of VIII
Summary
The quest for a perfect semiconductor that combines several features is a challenging task and a revived competitive scientific topic for materials scientists and engineers. Norouzzadeh et al extensively investigated the type-VIII gust-free Si46 by first-principles calculations, their results showed very promising thermoelectric features of this material [16,17,18]. First-principles calculations in the frame of the DFT within the GGA approach are employed to investigate the main structural features and the impact of hydrostatic pressure on the structural, electronic and elastic properties of type-VIII Ba8Si46 silicon clathrates, this paper is organized as follows: the first section outlines the theoretical approach including our computational details and structural aspects of the clathrate, the second section discusses the electronic properties under pressure, and the elastic properties under pressure are discussed in detail
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
