Chemical reduction of nanocrystalline CeO2

Zec, S.; Bošković, S.; Kaluđerović, Branka; Bogdanov, Ž.; Popović, N.

doi:10.1016/j.ceramint.2007.10.031

Cited by 25 publications

(10 citation statements)

References 15 publications

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“…If damage accumulation in CeO 2 is controlled largely by this material's redox behaviour, its radiation response should exhibit a strong dependence on grain size, as the presence of high-energy surfaces dramatically enhances the redox activity of CeO 2 (ref. 47). To test this hypothesis, nanocrystalline CeO 2 with an average crystallite size of 20 nm was irradiated.…”

Section: Resultsmentioning

confidence: 99%

Redox response of actinide materials to highly ionizing radiation

et al. 2015

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Energetic radiation can cause dramatic changes in the physical and chemical properties of actinide materials, degrading their performance in fission-based energy systems. As advanced nuclear fuels and wasteforms are developed, fundamental understanding of the processes controlling radiation damage accumulation is necessary. Here we report oxidation state reduction of actinide and analogue elements caused by high-energy, heavy ion irradiation and demonstrate coupling of this redox behaviour with structural modifications. ThO 2 , in which thorium is stable only in a tetravalent state, exhibits damage accumulation processes distinct from those of multivalent cation compounds CeO 2 (Ce 3 þ and Ce 4 þ ) and UO 3 (U 4 þ , U 5 þ and U 6 þ ). The radiation tolerance of these materials depends on the efficiency of this redox reaction, such that damage can be inhibited by altering grain size and cation valence variability. Thus, the redox behaviour of actinide materials is important for the design of nuclear fuels and the prediction of their performance.

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Section: Resultsmentioning

confidence: 99%

Redox response of actinide materials to highly ionizing radiation

et al. 2015

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“…[11, 12]. Recently, Zhang et al [13] reported that CeO 2 nanoparticles have great potential for multifunctional therapeutic applications in cancer therapy.…”

Section: Introductionmentioning

confidence: 99%

Room-Temperature Magnetism of Ceria Nanocubes by Inductively Transferring Electrons to Ce Atoms from Nearby Oxygen Vacancy

Kang

Guo

et al. 2015

Nano-Micro Lett.

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Ceria (CeO2) nanocubes were synthesized by a hydrothermal method and weak ferromagnetism was observed in room temperature. After ultraviolet irradiation, the saturation magnetization was significantly enhanced from ~3.18 × 10−3 to ~1.89 × 10−2 emu g−1. This is due to the increase of oxygen vacancies in CeO2 structure which was confirmed by X-ray photoelectron spectra. The first-principle calculation with Vienna ab-initio simulation package was used to illustrate the enhanced ferromagnetism mechanism after calculating the density of states (DOSs) and partial density of states (PDOSs) of CeO2 without and with different oxygen vacancies. It was found that the increase of oxygen vacancies will enlarge the PDOSs of Ce 4f orbital and DOSs. Two electrons in one oxygen vacancy are respectively excited to 4f orbital of two Ce atoms neighboring the vacancy, making these electron spin directions on 4f orbitals of these two Ce atoms parallel. This superexchange interaction leads to the formation of ferromagnetism in CeO2 at room temperature. Our work indicates that ultraviolet irradiation is an effective method to enhance the magnetism of CeO2 nanocube, and the first-principle calculation can understand well the enhanced magnetism.

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“…Nanocrystalline ceria powders have received great attention lately. They have been shown to exhibit higher catalytic activity, improved redox properties and a higher ionic conductivity in comparison with those of microcrystalline CeO 2 [7]. When pure CeO 2 is treated at high temperatures and under a reducing atmosphere, a removal of oxygen from the material takes place due to a partial reduction of Ce 4+ to Ce 3+ .…”

Section: Introductionmentioning

confidence: 99%