{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/245072"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/245072","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Local structure analysis of solid state ionic conductors, perovskite-derived structures by NMR and computational studies","abstract":"In this work, local environments of ions in solid oxide fuel cell (SOFC) electrolyte materials with perovskite and perovskite-derived crystallographic structures, i.e. $Ba_{2}In_{2}O_{5}$, $Ba_{2}(In_{1-x}Ga_{x})_{2}O_{5}$ and $Ba_{2}In_{2}O_{4}(OH)_{2}$, were investigated for their high ionic (O2– and H+) mobility at elevated temperatures. Two general methods were employed in this investigation; first, computational methods, such as density functional theory (DFT), gauge including projector augmented wave (GIPAW), cluster expansion (CE) and Monte Carlo simulations (MC); second, experimental methods, such as nuclear magnetic resonance (NMR), X-ray scattering (both powder diffraction and pair distribution function (PDF) analysis) and thermo-gravimetric analysis (TGA). The parent material, $Ba_{2}In_{2}O_{5}$, has inherent oxygen vacancies which allow for fast O2– ion mobility at elevated temperatures and for hydration of the material needless of doping. We improve a previous NMR study of $Ba_{2}In_{2}O_{5}$ by Adler et al. [1], assigning all three oxygen crystallographic sites to their relevant NMR peaks and investigate the high temperature structure. We then study the iso-valent doping of Ga into the In site resulting in Ba2(In1-xGax)2O5. While Yao et al. [2] find that Ga doping levels higher than 20% form a stable cubic structure, our findings indicate that Ga doping results in a phase segregation. However our findings for quenched samples are no different than those of Yao et al. [2]. Lastly we study the hydrated form of the parent material, $Ba_{2}In_{2}O_{4}(OH)_{2}$, which has high H+ ion mobility above 180C. We observe at least three possible hydrogen sites with local environments slightly different from the previous neutron diffraction study by Jayaraman et al. [3]. In contrast to the observation by Jayaraman et al. [3] of the hydrogen presence in all O2 layers we find an alternating occupancy of hydrogens in those layers.","abstract_html":"In this work, local environments of ions in solid oxide fuel cell (SOFC) electrolyte materials with perovskite and perovskite-derived crystallographic structures, i.e. <span class=\"etd-inline-math\">Ba<sub>2</sub>In<sub>2</sub>O<sub>5</sub></span>, <span class=\"etd-inline-math\">Ba<sub>2</sub>(In<sub>1-x</sub>Ga<sub>x</sub>)<sub>2</sub>O<sub>5</sub></span> and <span class=\"etd-inline-math\">Ba<sub>2</sub>In<sub>2</sub>O<sub>4</sub>(OH)<sub>2</sub></span>, were investigated for their high ionic (O2– and H+) mobility at elevated temperatures. Two general methods were employed in this investigation; first, computational methods, such as density functional theory (DFT), gauge including projector augmented wave (GIPAW), cluster expansion (CE) and Monte Carlo simulations (MC); second, experimental methods, such as nuclear magnetic resonance (NMR), X-ray scattering (both powder diffraction and pair distribution function (PDF) analysis) and thermo-gravimetric analysis (TGA). The parent material, <span class=\"etd-inline-math\">Ba<sub>2</sub>In<sub>2</sub>O<sub>5</sub></span>, has inherent oxygen vacancies which allow for fast O2– ion mobility at elevated temperatures and for hydration of the material needless of doping. We improve a previous NMR study of <span class=\"etd-inline-math\">Ba<sub>2</sub>In<sub>2</sub>O<sub>5</sub></span> by Adler et al. [1], assigning all three oxygen crystallographic sites to their relevant NMR peaks and investigate the high temperature structure. We then study the iso-valent doping of Ga into the In site resulting in Ba2(In1-xGax)2O5. While Yao et al. [2] find that Ga doping levels higher than 20% form a stable cubic structure, our findings indicate that Ga doping results in a phase segregation. However our findings for quenched samples are no different than those of Yao et al. [2]. Lastly we study the hydrated form of the parent material, <span class=\"etd-inline-math\">Ba<sub>2</sub>In<sub>2</sub>O<sub>4</sub>(OH)<sub>2</sub></span>, which has high H+ ion mobility above 180C. We observe at least three possible hydrogen sites with local environments slightly different from the previous neutron diffraction study by Jayaraman et al. [3]. In contrast to the observation by Jayaraman et al. [3] of the hydrogen presence in all O2 layers we find an alternating occupancy of hydrogens in those layers.","abstract_has_math":true,"creators":["Dervisoglu, Riza"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-10-08","date_published":"2013-10-08","updated_at":"2026-07-22T22:24:01Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/07a24900-102b-4163-8aab-52249950ca54/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.16294","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Dervisoglu, Riza"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2013-10-08"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/245072"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/07a24900-102b-4163-8aab-52249950ca54/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.16294"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/b6ad100a-d6b7-4d48-9cf0-dd38b92418ca/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this work, local environments of ions in solid oxide fuel cell (SOFC) electrolyte materials with perovskite and perovskite-derived crystallographic structures, i.e. $Ba_{2}In_{2}O_{5}$, $Ba_{2}(In_{1-x}Ga_{x})_{2}O_{5}$ and $Ba_{2}In_{2}O_{4}(OH)_{2}$, were investigated for their high ionic (O2– and H+) mobility at elevated temperatures. Two general methods were employed in this investigation; first, computational methods, such as density functional theory (DFT), gauge including projector augmented wave (GIPAW), cluster expansion (CE) and Monte Carlo simulations (MC); second, experimental methods, such as nuclear magnetic resonance (NMR), X-ray scattering (both powder diffraction and pair distribution function (PDF) analysis) and thermo-gravimetric analysis (TGA). The parent material, $Ba_{2}In_{2}O_{5}$, has inherent oxygen vacancies which allow for fast O2– ion mobility at elevated temperatures and for hydration of the material needless of doping. We improve a previous NMR study of $Ba_{2}In_{2}O_{5}$ by Adler et al. [1], assigning all three oxygen crystallographic sites to their relevant NMR peaks and investigate the high temperature structure. We then study the iso-valent doping of Ga into the In site resulting in Ba2(In1-xGax)2O5. While Yao et al. [2] find that Ga doping levels higher than 20% form a stable cubic structure, our findings indicate that Ga doping results in a phase segregation. However our findings for quenched samples are no different than those of Yao et al. [2]. Lastly we study the hydrated form of the parent material, $Ba_{2}In_{2}O_{4}(OH)_{2}$, which has high H+ ion mobility above 180C. We observe at least three possible hydrogen sites with local environments slightly different from the previous neutron diffraction study by Jayaraman et al. [3]. In contrast to the observation by Jayaraman et al. [3] of the hydrogen presence in all O2 layers we find an alternating occupancy of hydrogens in those layers."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["835269bda140c10400fe0606a14c3d21","c794476dccb0fab3fc9731f56f07ff96"]},{"key":"dc:title","label":"Title","values":["Local structure analysis of solid state ionic conductors, perovskite-derived structures by NMR and computational studies"]}]}],"canonical_facts":{"dc:creator":["Dervisoglu, Riza"],"dc:date.issued":["2013-10-08"],"dc:description.abstract":["In this work, local environments of ions in solid oxide fuel cell (SOFC) electrolyte materials with perovskite and perovskite-derived crystallographic structures, i.e. $Ba_{2}In_{2}O_{5}$, $Ba_{2}(In_{1-x}Ga_{x})_{2}O_{5}$ and $Ba_{2}In_{2}O_{4}(OH)_{2}$, were investigated for their high ionic (O2– and H+) mobility at elevated temperatures. Two general methods were employed in this investigation; first, computational methods, such as density functional theory (DFT), gauge including projector augmented wave (GIPAW), cluster expansion (CE) and Monte Carlo simulations (MC); second, experimental methods, such as nuclear magnetic resonance (NMR), X-ray scattering (both powder diffraction and pair distribution function (PDF) analysis) and thermo-gravimetric analysis (TGA). The parent material, $Ba_{2}In_{2}O_{5}$, has inherent oxygen vacancies which allow for fast O2– ion mobility at elevated temperatures and for hydration of the material needless of doping. We improve a previous NMR study of $Ba_{2}In_{2}O_{5}$ by Adler et al. [1], assigning all three oxygen crystallographic sites to their relevant NMR peaks and investigate the high temperature structure. We then study the iso-valent doping of Ga into the In site resulting in Ba2(In1-xGax)2O5. While Yao et al. [2] find that Ga doping levels higher than 20% form a stable cubic structure, our findings indicate that Ga doping results in a phase segregation. However our findings for quenched samples are no different than those of Yao et al. [2]. Lastly we study the hydrated form of the parent material, $Ba_{2}In_{2}O_{4}(OH)_{2}$, which has high H+ ion mobility above 180C. We observe at least three possible hydrogen sites with local environments slightly different from the previous neutron diffraction study by Jayaraman et al. [3]. In contrast to the observation by Jayaraman et al. [3] of the hydrogen presence in all O2 layers we find an alternating occupancy of hydrogens in those layers."],"dc:format.checksum.md5":["835269bda140c10400fe0606a14c3d21","c794476dccb0fab3fc9731f56f07ff96"],"dc:identifier.doi":["10.17863/CAM.16294"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/b6ad100a-d6b7-4d48-9cf0-dd38b92418ca/download"],"dc:language":["en"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/245072"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/07a24900-102b-4163-8aab-52249950ca54/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:title":["Local structure analysis of solid state ionic conductors, perovskite-derived structures by NMR and computational studies"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:01Z"}