First principles electronic and elastic properties of fresnoite Ba2TiSi2O8
Electronic, structural and elastic properties of fresnoite, $ \newcommand{\btso}{{\rm Ba_2TiSi_2O_8}} \btso$ (BTSO), are obtained via first principles calculations. The electronic properties having been comparatively analysed using both the generalised gradient approximation and the hybrid functiona...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | Materials Research Express |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/2053-1591/aa99e8 |
| _version_ | 1797747334156648448 |
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| author | Ned Thaddeus Taylor Francis Huw Davies S P Hepplestone |
| author_facet | Ned Thaddeus Taylor Francis Huw Davies S P Hepplestone |
| author_sort | Ned Thaddeus Taylor |
| collection | DOAJ |
| description | Electronic, structural and elastic properties of fresnoite, $ \newcommand{\btso}{{\rm Ba_2TiSi_2O_8}} \btso$ (BTSO), are obtained via first principles calculations. The electronic properties having been comparatively analysed using both the generalised gradient approximation and the hybrid functional method. The indirect band gap of BTSO is found to change significantly through the choice of functional; it shows an increase from 3.79 eV to 5.72 eV. A small indirect gap of 0.33 eV is also present directly above the conduction band edge, which allows for small optical transitions similar to that of defect transitions. The titanium orbitals are dominant near the conduction band edge, with oxygen orbitals being the main contributor to the valence band edge. Dielectric and elastic properties of the material are also obtained, with the bulk modulus being 131.73 GPa and the elastic moduli along the [1 0 0] and [0 0 1] directions being 180.57 GPa and 102.56 GPa, respectively. Theoretical values for Raman frequencies are reported for BTSO. Finally, Bader charge analysis reveals the barium and titanium atoms in BTSO are comparable to their charges in $ \newcommand{\bto}{{\rm BaTiO_3}} \bto$ . However, due to the presence of the Si–O bonds, oxygen exhibits a significant charge redistribution. Through the choice of functional, charge can become more localised on the oxygen atoms. |
| first_indexed | 2024-03-12T15:49:17Z |
| format | Article |
| id | doaj.art-c1e9d9ac68324ef087d5442aa8b68dda |
| institution | Directory Open Access Journal |
| issn | 2053-1591 |
| language | English |
| last_indexed | 2024-03-12T15:49:17Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Materials Research Express |
| spelling | doaj.art-c1e9d9ac68324ef087d5442aa8b68dda2023-08-09T15:18:19ZengIOP PublishingMaterials Research Express2053-15912017-01-0141212590410.1088/2053-1591/aa99e8First principles electronic and elastic properties of fresnoite Ba2TiSi2O8Ned Thaddeus Taylor0https://orcid.org/0000-0002-9134-9712Francis Huw Davies1https://orcid.org/0000-0003-0786-2773S P Hepplestone2https://orcid.org/0000-0002-2528-1270Department of Physics, University of Exeter , Stocker Road, Exeter, EX4 4QL, United KingdomDepartment of Physics, University of Exeter , Stocker Road, Exeter, EX4 4QL, United KingdomDepartment of Physics, University of Exeter , Stocker Road, Exeter, EX4 4QL, United KingdomElectronic, structural and elastic properties of fresnoite, $ \newcommand{\btso}{{\rm Ba_2TiSi_2O_8}} \btso$ (BTSO), are obtained via first principles calculations. The electronic properties having been comparatively analysed using both the generalised gradient approximation and the hybrid functional method. The indirect band gap of BTSO is found to change significantly through the choice of functional; it shows an increase from 3.79 eV to 5.72 eV. A small indirect gap of 0.33 eV is also present directly above the conduction band edge, which allows for small optical transitions similar to that of defect transitions. The titanium orbitals are dominant near the conduction band edge, with oxygen orbitals being the main contributor to the valence band edge. Dielectric and elastic properties of the material are also obtained, with the bulk modulus being 131.73 GPa and the elastic moduli along the [1 0 0] and [0 0 1] directions being 180.57 GPa and 102.56 GPa, respectively. Theoretical values for Raman frequencies are reported for BTSO. Finally, Bader charge analysis reveals the barium and titanium atoms in BTSO are comparable to their charges in $ \newcommand{\bto}{{\rm BaTiO_3}} \bto$ . However, due to the presence of the Si–O bonds, oxygen exhibits a significant charge redistribution. Through the choice of functional, charge can become more localised on the oxygen atoms.https://doi.org/10.1088/2053-1591/aa99e8fresnoitefirst principles calculationshybrid functionalband gap correctionbarium titanate |
| spellingShingle | Ned Thaddeus Taylor Francis Huw Davies S P Hepplestone First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 Materials Research Express fresnoite first principles calculations hybrid functional band gap correction barium titanate |
| title | First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 |
| title_full | First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 |
| title_fullStr | First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 |
| title_full_unstemmed | First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 |
| title_short | First principles electronic and elastic properties of fresnoite Ba2TiSi2O8 |
| title_sort | first principles electronic and elastic properties of fresnoite ba2tisi2o8 |
| topic | fresnoite first principles calculations hybrid functional band gap correction barium titanate |
| url | https://doi.org/10.1088/2053-1591/aa99e8 |
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