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DOE OSTI · 1774530

Electronic coupling in square planar La 4 Ni 3 O 8

Upton, M. H.·Zhang, Junjie·Zheng, Hong·Said, A.·Mitchell, J. F.
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Abstract

A study of a dd excitation in La4Ni 3 O 8 (La-438) using x-ray absorption scattering (XAS) and resonant inelastic x-ray scattering (RIXS) at the Ni K-edge is presented here. The incident energy dependence of this dd excitation shows a maximum at the 1s→4p π transition. Its intensity at the main edge is proportional to the amount of incident x-ray polarization parallel to the c-axis. These observations suggest that the RIXS process underlying this excitation includes a strong Ni 3d-Ni 4p Coulomb interaction and excludes the “4p-as-spectator” approximation. The dominant Ni 3d Coulomb interaction is with Ni 4p π with limited or no interaction with the Ni 4p σ . An insulating gap closing is observed as a function of temperature.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYelectronic structurenickelateresonant inelastic x-ray scatteringsquare planar

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Upton, M. H., Zhang, Junjie, Zheng, Hong, Said, A., Mitchell, J. F.. 2020-07-28. Electronic coupling in square planar La 4 Ni 3 O 8. https://doi.org/10.1088/1361-648x%2Faba314

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