Photoelectron spectroscopy and diffraction of surface nanoscale NbO/Nb(110) structures

Kuznetsov, M. V.; Razinkin, A. S.; Шалаева, Е. В.

doi:10.1007/s10947-009-0079-y

Cited by 35 publications

(22 citation statements)

References 6 publications

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“…Since XPS is surface analysing technique, this observation must be due to surface oxidation of NbO as XRD (not shown here) reveals the existence of NbO as a major phase. XPS spectra of Nb 2 O 5 and NbO 2 show the binding energies corresponding to Nb 3d5/2 bands in line with the literature [17,18]. On comparing the spectra of sample a and sample c in fig.…”

Section: Resultssupporting

confidence: 84%

Catalytic modification in dehydrogenation properties of KSiH₃

Jain

Ichikawa

Yamaguchi

et al. 2014

Phys. Chem. Chem. Phys.

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A number of known catalysts, which have been proven to be very effective for several hydrogen species, were studied in order to determine their effects on the hydrogen ab/desorption properties of KSiH3. Among all the catalysts used in this work, mesoporous Nb2O5 is found to be quite effective, with a reduction in activation energy from 142 kJ mol(-1) for pristine KSi to 63 kJ mol(-1) for mesoporous-Nb2O5-added KSi, thus allowing desorption to start at 100-120 °C. Any disproportionation is not observed in the controlled hydrogenation process. The mechanism for this improvement is also proposed in detail. The kinetic modifications on the ab/desorption properties of KSiH3 provide an alternative to the well-known family of heavy BCC alloys which are capable of working in the same temperature range but with a lower gravimetric hydrogen content, almost half of the KSi system.

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Section: Resultssupporting

confidence: 84%

Catalytic modification in dehydrogenation properties of KSiH₃

Jain

Ichikawa

Yamaguchi

et al. 2014

Phys. Chem. Chem. Phys.

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“…These are conventionally assigned as originating from Nb 4þ and Nb 5þ oxidation states, respectively, in the literature. 57,58 However, we believe that the multi-component nature of the Nb 3d core level of NbO 2 is due to final-state effects, 59,60 and not to the presence of Nb 2 O 5 . We cannot rule out, however, the existence of a thin Nb 2 O 5 overlayer in the films measured with ellipsometry as the uncapped NbO 2 films have to be exposed to air for several days prior to ellipsometric measurements.…”

Section: Optical Properties Via Ellipsometry and Theorymentioning

confidence: 82%

Electronic and optical properties of NbO2

O’Hara

Nunley

Posadas

et al. 2014

Journal of Applied Physics

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In the present study, we combine theoretical and experimental approaches in order to gain insight into the electronic properties of both the high-temperature, rutile (metallic) and low-temperature, body-centered tetragonal (insulating) phase of niobium dioxide (NbO2) as well as the optical properties of the low-temperature phase. Theoretical calculations performed at the level of the local density approximation, Hubbard U correction, and hybrid functional are complemented with the spectroscopic ellipsometry (SE) of epitaxial films grown by molecular beam epitaxy. For the rutile phase, the local density approximation (LDA) gives the best description and predicts Fermi surface nesting consistent with wave vectors that lead to niobium-niobium dimerization during the phase transition. For the insulating phase, LDA provides a good quantitative description of the lattice, but only a qualitative description for the band gap. Including a Hubbard U correction opens the band gap at the expense of correctly describing the valence band and lattice of both phases. The hybrid functional slightly overestimates the band gap. Ellipsometric measurement is consistent with insulating behavior with a 1.0 eV band gap. Comparison with the theoretical dielectric functions, obtained utilizing a scissors operator to adjust the LDA band gap to reproduce the ellipsometry data, allows for identification of the SE peak features.

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“…Furthermore, the batteries are reusable after the replacement of an old separator with a new one. These results strongly suggest that high voltage operation poses a risk for higher capacity fade due to impedance growth and short circuit formation caused by oxidative decomposition of electrolytes following LiF and metal-F 2 formation and Mn 2+ dissolution during the cycles [29][30][31][32] .…”

Section: Resultsmentioning

confidence: 99%

High-voltage capabilities of ultra-thin Nb₂O₅nanosheet coated LiNi_1/3Co_1/3Mn_1/3O₂cathodes

et al. 2016

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In this study, we propose coating the surface of LiNi1/3Co1/3Mn1/3O2 (NCM) electrodes with 1.1 nm Nb2O5 nanosheets as a new way for enhancing their high-voltage capabilities in glavanostatic charge-discharge performances and long-term storage of the charged state at 60 o C. The coatings suppress the oxidative decomposition of the electrolyte and disordering the layered structures on the NCM surface, which result in impedance growth. After 100 cycles at voltage ranges 4.6 V-2.8 V at 1 C rate, more than 70% of the initial discharge capacity was retained in the coated electrodes. In comparison, the discharge capacity completely faded in the bare NCM cathode. Furthermore, the nanosheet coatings stabilize the delithiated NCM lattice charged at 4.6V and inhibit current generation based on the electrode reactions at 60 o C for 300 h.

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Photoelectron spectroscopy and diffraction of surface nanoscale NbO/Nb(110) structures

Cited by 35 publications

References 6 publications

Catalytic modification in dehydrogenation properties of KSiH₃

Catalytic modification in dehydrogenation properties of KSiH₃

Electronic and optical properties of NbO2

High-voltage capabilities of ultra-thin Nb₂O₅nanosheet coated LiNi_1/3Co_1/3Mn_1/3O₂cathodes

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Photoelectron spectroscopy and diffraction of surface nanoscale NbO/Nb(110) structures

Cited by 35 publications

References 6 publications

Catalytic modification in dehydrogenation properties of KSiH3

Catalytic modification in dehydrogenation properties of KSiH3

Electronic and optical properties of NbO2

High-voltage capabilities of ultra-thin Nb2O5nanosheet coated LiNi1/3Co1/3Mn1/3O2cathodes

Contact Info

Product

Resources

About

Catalytic modification in dehydrogenation properties of KSiH₃

Catalytic modification in dehydrogenation properties of KSiH₃

High-voltage capabilities of ultra-thin Nb₂O₅nanosheet coated LiNi_1/3Co_1/3Mn_1/3O₂cathodes