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First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam

The electronic, phase stability, epitaxial strain, and thermoelectric properties of cubic(P3mm) and tetragonal (P4mm) structures of PTO and Sn TO were investigated using density functional theory (DFT). Cubic and tetragonal structures within the GGA-PBE and GGA PBE-sol functional were applied in a p...

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Main Author: Md Jahangir Alam, Nurakma Natasya
Format: Thesis
Language:English
Published: 2023
Subjects:
Electricity
Online Access:https://ir.uitm.edu.my/id/eprint/88788/2/88788.pdf
https://ir.uitm.edu.my/id/eprint/88788/
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spelling my.uitm.ir.887882024-01-17T01:22:03Z https://ir.uitm.edu.my/id/eprint/88788/ First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam Md Jahangir Alam, Nurakma Natasya Electricity The electronic, phase stability, epitaxial strain, and thermoelectric properties of cubic(P3mm) and tetragonal (P4mm) structures of PTO and Sn TO were investigated using density functional theory (DFT). Cubic and tetragonal structures within the GGA-PBE and GGA PBE-sol functional were applied in a pseudo-potential plane wave using the CASTEP computer code respectively. The results showed that the tetragonal PTO and SnTO have the lowest cohesive energy of -39.320 eV and -39.523 eV respectively. Cubic PTO has an indirect band gap of 1.691 eV and SnTO is 1.164 eV while in the tetragonal phase, the band gap value of PTO and Sn TO is 1.703 eV and 1.016 eV, respectively. In the PTO structure, the bond between Pb and O is ionic in the tetragonal state, while there is strong hybridization between Ti-3d and O-2p, which is significant for ferroelectricity. It is shown that the tetragonal is the most stable structure since it has the smallest cohesive energy compared to other structures. The out-of-plane c-axis strain is shown to be largely oriented to PTO under large in-plane a-axis compressive strain. The effect of epitaxial strain proved the surface compatibility in thin film applications. It shows that PTO and SnTO are suitable for surface cleaving. The cubic PbO terminated surface in PTO has a band gap of 1.572 eV gap which is almost equivalent to the bulk structure which is 1.691 eV compared to the TiO2 terminated surface which is 1.366 eV. The type-I surface of SnTO has an indirect band gap of 1.159eV, whereas the type-II surface has a band gap of 1.196 eV. PTO has emerged as a promising material for thermoelectric application. In this study, the underlying mechanism to improve the thermoelectric efficiency of ATiO3 were determined. The thermoelectric parameters of the designed surface structures have been obtained by using the Boltzmann transport equation approximation in the WIEN2K computer code. The properties of the structure, electronic, and thermoelectricity were calculated and analyzed. The surface (001) modification through the AO termination layer has increased the electrical conductivity, thus increasing the power factor. On the other hand, increasing the See beck coefficient, lowering the thermal conductivity and thermopower, improves the figure of merit. It is shown that the thermo electric performance of surface (001) cubic SnTO is higher as compared to PTO making it interesting for lead-free materials in thin-film applications. 2023 Thesis NonPeerReviewed text en https://ir.uitm.edu.my/id/eprint/88788/2/88788.pdf First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam. (2023) PhD thesis, thesis, Universiti Teknologi MARA (UiTM). <http://terminalib.uitm.edu.my/88788.pdf>
institution Universiti Teknologi Mara
building Tun Abdul Razak Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Teknologi Mara
content_source UiTM Institutional Repository
url_provider http://ir.uitm.edu.my/
language English
topic Electricity
spellingShingle Electricity
Md Jahangir Alam, Nurakma Natasya
First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
description The electronic, phase stability, epitaxial strain, and thermoelectric properties of cubic(P3mm) and tetragonal (P4mm) structures of PTO and Sn TO were investigated using density functional theory (DFT). Cubic and tetragonal structures within the GGA-PBE and GGA PBE-sol functional were applied in a pseudo-potential plane wave using the CASTEP computer code respectively. The results showed that the tetragonal PTO and SnTO have the lowest cohesive energy of -39.320 eV and -39.523 eV respectively. Cubic PTO has an indirect band gap of 1.691 eV and SnTO is 1.164 eV while in the tetragonal phase, the band gap value of PTO and Sn TO is 1.703 eV and 1.016 eV, respectively. In the PTO structure, the bond between Pb and O is ionic in the tetragonal state, while there is strong hybridization between Ti-3d and O-2p, which is significant for ferroelectricity. It is shown that the tetragonal is the most stable structure since it has the smallest cohesive energy compared to other structures. The out-of-plane c-axis strain is shown to be largely oriented to PTO under large in-plane a-axis compressive strain. The effect of epitaxial strain proved the surface compatibility in thin film applications. It shows that PTO and SnTO are suitable for surface cleaving. The cubic PbO terminated surface in PTO has a band gap of 1.572 eV gap which is almost equivalent to the bulk structure which is 1.691 eV compared to the TiO2 terminated surface which is 1.366 eV. The type-I surface of SnTO has an indirect band gap of 1.159eV, whereas the type-II surface has a band gap of 1.196 eV. PTO has emerged as a promising material for thermoelectric application. In this study, the underlying mechanism to improve the thermoelectric efficiency of ATiO3 were determined. The thermoelectric parameters of the designed surface structures have been obtained by using the Boltzmann transport equation approximation in the WIEN2K computer code. The properties of the structure, electronic, and thermoelectricity were calculated and analyzed. The surface (001) modification through the AO termination layer has increased the electrical conductivity, thus increasing the power factor. On the other hand, increasing the See beck coefficient, lowering the thermal conductivity and thermopower, improves the figure of merit. It is shown that the thermo electric performance of surface (001) cubic SnTO is higher as compared to PTO making it interesting for lead-free materials in thin-film applications.
format Thesis
author Md Jahangir Alam, Nurakma Natasya
author_facet Md Jahangir Alam, Nurakma Natasya
author_sort Md Jahangir Alam, Nurakma Natasya
title First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
title_short First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
title_full First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
title_fullStr First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
title_full_unstemmed First-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) ATiO3 (A=Pb, Sn) using Density Functional Theory (DFT) / Nurakma Natasya Md Jahangir Alam
title_sort first-principles study on structural, electronic and thermoelectric properties of bulk and surface (001) atio3 (a=pb, sn) using density functional theory (dft) / nurakma natasya md jahangir alam
publishDate 2023
url https://ir.uitm.edu.my/id/eprint/88788/2/88788.pdf
https://ir.uitm.edu.my/id/eprint/88788/
_version_ 1789429243859435520
score 13.211869

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