Electronic structure study of Co doped CeO2 nanoparticles using X-ray absorption fine structure spectroscopy

Kumar, Shalendra; Gautam, Sanjeev; Song, Tae Kwon; Chae, Keun Hwa; Jang, Ki Wan; Kim, S.S.

doi:10.1016/j.jallcom.2014.05.025

Cited by 34 publications

(13 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reduction in the amplitude of the FT intensity could be ascribed to the defective crystalline lattice in the doped samples. 30,31 CN, R, and s 2 were obtained from the EXAFS analysis of Zr K and Hf L 3 -edges and tabulated in Table 2. It is clear from Table 2 that the Zr-Ce and Hf-Ce bond distances, obtained from the Zr K-edge and Hf-L 3 -edge EXAFS fitted data, are close to that estimated from the Ce K-edge EXAFS data fittings.…”

Section: Resultsmentioning

confidence: 99%

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Sharma

Varshney

Shin

et al. 2014

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Single phase nanoparticles (NPs) of CeO2, Ce0.5Zr0.5O2, Ce0.5Hf0.5O2 and Ce0.5Hf0.25Zr0.25O2 were successfully synthesized by co-precipitation method at constant pH and temperature. The X-ray diffraction results revealed that the additive atoms did not segregate to form secondary phases but led to grain size variation in the NPs. The 10 Dq values in the near edge X-ray absorption fine structure (NEXAFS) spectra at the O K-edge did not vary in the same way as the average grain size was changed for the doped CeO2 NPs. The deconvolution of Ce M5-edge and detailed analysis of O K pre-edge peak have shown the higher Ce(+3)/(Ce(+3) + Ce(+4)) ratio in the Zr- and Hf-doped samples. The local atomic structure around the Ce, Zr and Hf atoms was investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy at Ce K-edge, Zr K-edge and Hf L3-edge, respectively, and the EXAFS data were fitted with the theoretical calculations. The 4f occupancy, Ce(+3)/(Ce(+3) + Ce(+4)) ratio of Ce ions, coordination number of Ce and Ce-Ce/Ce-O bond distances were sensitive to the additive atoms but not explicitly changed according to the grain size variation in the NPs.

show abstract

Section: Resultsmentioning

confidence: 99%

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Sharma

Varshney

Shin

et al. 2014

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In particular, the local structure in a specific atom can be analyzed using EXAFS. Low-to-medium-energy synchrotron facilities are relatively accessible, so most of the XAFS analysis for cerianite has been conducted at the cerium L III -edge (5.7 × 10 3 eV) [29][30][31]. The EXAFS analysis at the cerium L III -edge has a somewhat lower accuracy for derived structural parameters due to its limited data range, arising from the small energy separation between the L III -and L II -edges [29][30][31].…”

Section: X-ray Absorption Fine Structure Analysis At Cerium K-edgementioning

confidence: 99%

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

et al. 2019

View full text Add to dashboard Cite

Prolonged high-intensity grinding can modify the crystal structure of solid substances and/or induce chemical reaction, which is referred to as mechanochemical reaction. Such reactions can exert positive influences on hydrometallurgical processes, therefore, many researchers have applied mechanochemical reactions for metals dissolution from minerals. The mechanism of mechanochemical reaction has been investigated using solid analyses and simulations. Structural changes caused by mechanochemical reactions are not yet sufficiently clarified because the ground samples are amorphous. The objective of this study was to analyze structural changes of cerianite in weathered residual rare earth ore by mechanochemical reduction. The ore was ground by planetary ball milling for 10, 60 and 720 min. Structural change was analyzed by the X-ray absorption near-edge structure and extended x-ray absorption fine structure analysis at the cerium LIII- and K-edges. These analyses revealed that the structural change of cerianite in this ore induced by mechanochemical reduction involved oxygen vacancy production. The process of the oxygen vacancy formation was closely coupled with the quantum effect of localization–delocalization of the 4f electron of cerium.

show abstract

“…Low-to-medium-energy synchrotron facilities are relatively accessible, so most XAFS analysis for cerianite has been conducted at the cerium LIII-edge (5.7 × 10 3 eV) [25][26][27]. EXAFS analysis at the cerium LIII-edge has somewhat lower accuracy for derived structural parameters due to its limited data range, arising from the small energy separation between the LIII-and LII-edges [25][26][27]. When XAFS analysis for cerianite was conducted at the cerium K-edge (4.0 × 10 4 eV), more accurate local structure around the cerium atom could be obtained because of the larger EXAFS data range, as described previously [28].…”

Section: X-ray Absorption Fine Structure Analysis At Cerium K-edgementioning

confidence: 99%

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-ray Absorption Fine Structure

Kato¹,

Tsunazawa

Liu

et al. 2019

Preprint

View full text Add to dashboard Cite

Prolonged high-intensity grinding can modify the crystal structure of solid substances and/or induce chemical reaction, which is referred to as mechanochemical reaction. Such reactions can exert positive influences on hydrometallurgical processes, therefore, many researchers have applied mechanochemical reactions for metals dissolution from minerals. The mechanism of mechanochemical reaction has been investigated using solid analyses and simulations. Structural changes caused by mechanochemical reaction are not yet sufficiently clarified because the ground samples are amorphous. The objective of this study was to analyze structural changes of cerianite in weathered residual rare earth ore by mechanochemical reduction. Structural change was analyzed by x-ray absorption near-edge structure and extended x-ray absorption fine structure analysis at the cerium LIII- and K-edges. These analyses revealed that the structural change of cerianite in this ore induced by mechanochemical reduction involved oxygen vacancy production. The process of the oxygen vacancy formation was closely coupled with the quantum effect of localization–delocalization of the 4f electron of cerium.

show abstract

Electronic structure study of Co doped CeO2 nanoparticles using X-ray absorption fine structure spectroscopy

Cited by 34 publications

References 28 publications

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-ray Absorption Fine Structure

Contact Info

Product

Resources

About

Electronic structure study of Co doped CeO2 nanoparticles using X-ray absorption fine structure spectroscopy

Cited by 34 publications

References 28 publications

Electronic structure study of Ce1−xAxO2 (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Electronic structure study of Ce1−xAxO2 (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-ray Absorption Fine Structure

Contact Info

Product

Resources

About

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations

Electronic structure study of Ce_1−xA_xO₂ (A = Zr & Hf) nanoparticles: NEXAFS and EXAFS investigations