English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a combined experimental and theoretical investigation on the orbital occupation and local symmetry of Co in ${\text{Na}}_{x}{\text{CoO}}_{2}$. We have carried out polarization dependent $\text{Co}\ensuremath{-}{L}_{2,3}$ soft x-ray absorption spectroscopy measurements. By comparing the spectra with the results of configuration-interaction cluster calculations which include the full-atomic multiplet theory, we have found that the local symmetry for the Co ions are well-described by the ${D}_{3d}$ point group with intermixing between the cubic ${t}_{2g}^{\ifmmode\pm\else\textpm\fi{}}$ and ${e}_{g}^{\ifmmode\pm\else\textpm\fi{}}$ orbitals. We have determined that the ${t}_{2g}$ holes in both the ${\text{Na}}_{0.75}{\text{CoO}}_{2}$ and ${\text{Na}}_{0.5}{\text{CoO}}_{2}$ compositions reside mainly in the ${a}_{1g}$ orbital. The spectroscopically deduced ${\text{Co}}^{4+}/{\text{Co}}^{3+}$ ratio agrees well with the nominal Na concentration. We discuss the surprising observation that the single-site cluster approach is still adequate to reproduce the spectra despite the mixed valent character of the Co ions in this compound.

physical review. b, condensed matter and materials physics

Local orbital occupation and energy levels of Co in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Na</mml:mtext></mml:mrow><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mrow><mml:mtext>CoO</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>: A soft x-ray absorption study

Local orbital occupation and energy levels of Co inNaxCoO2: A soft x-ray absorption study