Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate

Detalhes bibliográficos
Autor(a) principal: Tkach, Alexander
Data de Publicação: 2018
Outros Autores: Amaral, Luís, Vilarinho, Paula M., Senos, Ana M.R.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10773/37459
Resumo: Titanium-rich (Sr/Ti = 0.995) strontium titanate (ST) ceramics, air-sintered in a temperature range of 1400–1625 °C, were reported to possess anomalies in the grain growth and analogous anomalies in the grain boundary (GB) conductivity activation energy. However, these two interface-related phenomena, occurring at GBs, could not be associated with each other using a simple “brick-layer” model. In this work we revise the topic and advocate that the deviation from the model comes from the oxygen vacancies localized at GBs of the rapidly-cooled ST ceramics. To verify this, we annealed the ceramics in oxygen and performed their systematic and comparative analysis using impedance spectroscopy. A levelling-off in the GB conductivity activation energy, which increases for ≤1.24 eV, and a four-fold decrease in the GB permittivity are observed after annealing. Thus, we confirm a key role of oxygen vacancies in relation between the grain growth and GB conductivity anomalies of as-sintered Ti-rich ST ceramics.
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spelling Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanateStrontium titanateGrain boundary specific areaVacanciesOxygen annealingImpedance spectroscopyCharge transportConduction mechanismTitanium-rich (Sr/Ti = 0.995) strontium titanate (ST) ceramics, air-sintered in a temperature range of 1400–1625 °C, were reported to possess anomalies in the grain growth and analogous anomalies in the grain boundary (GB) conductivity activation energy. However, these two interface-related phenomena, occurring at GBs, could not be associated with each other using a simple “brick-layer” model. In this work we revise the topic and advocate that the deviation from the model comes from the oxygen vacancies localized at GBs of the rapidly-cooled ST ceramics. To verify this, we annealed the ceramics in oxygen and performed their systematic and comparative analysis using impedance spectroscopy. A levelling-off in the GB conductivity activation energy, which increases for ≤1.24 eV, and a four-fold decrease in the GB permittivity are observed after annealing. Thus, we confirm a key role of oxygen vacancies in relation between the grain growth and GB conductivity anomalies of as-sintered Ti-rich ST ceramics.Elsevier2023-04-28T14:48:18Z2018-06-01T00:00:00Z2018-06info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/37459eng0955-221910.1016/j.jeurceramsoc.2018.01.014Tkach, AlexanderAmaral, LuísVilarinho, Paula M.Senos, Ana M.R.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T12:12:21Zoai:ria.ua.pt:10773/37459Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:08:04.238491Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
title Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
spellingShingle Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
Tkach, Alexander
Strontium titanate
Grain boundary specific area
Vacancies
Oxygen annealing
Impedance spectroscopy
Charge transport
Conduction mechanism
title_short Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
title_full Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
title_fullStr Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
title_full_unstemmed Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
title_sort Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate
author Tkach, Alexander
author_facet Tkach, Alexander
Amaral, Luís
Vilarinho, Paula M.
Senos, Ana M.R.
author_role author
author2 Amaral, Luís
Vilarinho, Paula M.
Senos, Ana M.R.
author2_role author
author
author
dc.contributor.author.fl_str_mv Tkach, Alexander
Amaral, Luís
Vilarinho, Paula M.
Senos, Ana M.R.
dc.subject.por.fl_str_mv Strontium titanate
Grain boundary specific area
Vacancies
Oxygen annealing
Impedance spectroscopy
Charge transport
Conduction mechanism
topic Strontium titanate
Grain boundary specific area
Vacancies
Oxygen annealing
Impedance spectroscopy
Charge transport
Conduction mechanism
description Titanium-rich (Sr/Ti = 0.995) strontium titanate (ST) ceramics, air-sintered in a temperature range of 1400–1625 °C, were reported to possess anomalies in the grain growth and analogous anomalies in the grain boundary (GB) conductivity activation energy. However, these two interface-related phenomena, occurring at GBs, could not be associated with each other using a simple “brick-layer” model. In this work we revise the topic and advocate that the deviation from the model comes from the oxygen vacancies localized at GBs of the rapidly-cooled ST ceramics. To verify this, we annealed the ceramics in oxygen and performed their systematic and comparative analysis using impedance spectroscopy. A levelling-off in the GB conductivity activation energy, which increases for ≤1.24 eV, and a four-fold decrease in the GB permittivity are observed after annealing. Thus, we confirm a key role of oxygen vacancies in relation between the grain growth and GB conductivity anomalies of as-sintered Ti-rich ST ceramics.
publishDate 2018
dc.date.none.fl_str_mv 2018-06-01T00:00:00Z
2018-06
2023-04-28T14:48:18Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10773/37459
url http://hdl.handle.net/10773/37459
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 0955-2219
10.1016/j.jeurceramsoc.2018.01.014
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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