resumo
In this work, the formation of the orthorhombic phase of ZrO2 together with the minor monoclinic phase were elucidated by X-ray diffraction and transmission electron microscopy. Moreover, oxidized W can be responsible for the formation of oxygen vacancies in the ZrO2 through oxygen scavenging. The ferroelectric properties of the W/ZrO2/W film capacitors were investigated through piezoresponse force microscopy (PFM) and polarizationvoltage measurements. A second-order phase transition from the polar orthorhombic phase to the non-polar tetragonal phase was observed. Density functional theory calculations confirm our experimental results and propose that oxygen vacancies are responsible for the Curie-Weiss temperature of 130 degrees C, significantly lower than the theoretical value for the bulk.
palavras-chave
TOTAL-ENERGY CALCULATIONS; CAPACITORS
categoria
Engineering; Materials Science; Physics
autores
Pereira, RMP; Istrate, MC; Figueiras, FG; Lenzi, V; Silva, BM; Benamara, M; Romanyuk, KN; Ghica, C; Almeida, BG; Marques, L; Pereira, M; Silva, JPB
nossos autores
Fábio Gabriel Nazário Figueiras
Bolseiro de pós-Doutoramento
Konstantin Nikolaevich Romanyuk
Investigador Júnior
Veniero Lenzi
Bolseiro de pós-DoutoramentoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was supported by: (i) the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020 (ii) exploratory projects 2022.01740.PDTC and EXPL/FIS-MAC/0947/2021, (iii) the European Union's Horizon 2020 research and innovation programme under grant agreement No 958174 (M-ERA-NET3/0003/2021 - NanOx4EStor) and (iii) Project NECL - NORTE-01-0145-FEDER-022096 and Project UID/NAN/50024/ 2019. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). It is also funded by national funds (OE), through FCT Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.