visitant ::
identificació
|
|||||||||||||||
Cerca | Lliura | Ajuda | Servei de Biblioteques | Sobre el DDD | Català English Español |
Pàgina inicial > Articles > Articles publicats > Oxidation processes at the surface of BaTiO3 thin films under environmental conditions |
Data: | 2021 |
Resum: | Dissociation and adsorption of water on ferroelectric oxide surfaces play important role in the processes of screening and switching dynamics of ferroelectric polarization, as well as in catalytic processes which can be additionally coupled with light, temperature or vibration stimuli. In this work, we present XPS study of ferroelectric BaTiOthin films and determine the entanglement between surface chemistry, polarization direction and stability, by observing changes upon time exposure to environmental conditions, heating in Oatmosphere and irradiation in vacuum. We devote special attention to Ba 3d spectral region and identify two different oxidation states of O atoms in the compounds of Ba. While this second specie was generally attributed to Ba in surface compounds where it has different oxygen coordination than in the bulk, based on the XPS results of oxygen annealed thin films, we demonstrate that this so far neglected component, corresponds to barium peroxide (BaO) and identify it as important active specie for the study of screening mechanisms closely related with catalytic activity present in this ferroelectric material. Finally, we report on chemically assisted polarization switching in thin films induced by heating in vacuum or exposure to X-Ray radiation due to the formation of positive surface electric field created by oxygen or electron vacancies, respectively. |
Ajuts: | Agencia Estatal de Investigación CEX2019-000917-S Agencia Estatal de Investigación SEV-2017-0706 Ministerio de Ciencia e Innovación PID2019-110907GB-I00 Ministerio de Ciencia e Innovación PID2019-109931GB-I00 Ministerio de Ciencia e Innovación FIS2015-73932-JIN Agència de Gestió d'Ajuts Universitaris i de Recerca 2017-SGR-579 |
Nota: | Altres ajuts: the ICN2 is funded by the CERCA programme/Generalitat de Catalunya. I. S. acknowledges support of the Secretaria d'Universitats i Recerca - Departament d'Empresa i Coneixement - Generalitat de Catalunya and the European Social Fund (ESF) (FI grant reference 2020 FI_B2 00157). |
Drets: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades. |
Llengua: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Matèria: | XPS ; BaTiO3 thin films ; Ferroelectric materials ; BaO2 ; Surface oxidation ; Water splitting |
Publicat a: | Applied surface science, Vol. 565 (Nov. 2021) , art. 150288, ISSN 0169-4332 |
9 p, 3.3 MB |