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Updated: Dec 15, 2025
11:54
Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
10.6K
Electronic coupling in square planar La4Ni3O8
M H Upton1, Junjie Zhang2,3, Hong Zheng2
1Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, United States of America.
Summary
Resonant inelastic x-ray scattering reveals strong Ni 3d-Ni 4p Coulomb interactions in La4Ni3O8, influencing dd excitations. An insulating gap closes with increasing temperature.
Area of Science:
- Condensed Matter Physics
- Materials Science
- X-ray Spectroscopy
Background:
- La4Ni3O8 (La-438) is a material exhibiting complex electronic properties.
- Understanding electronic excitations is crucial for characterizing materials.
Purpose of the Study:
- To investigate dd excitations in La-438 using advanced x-ray scattering techniques.
- To elucidate the underlying physical mechanisms of these excitations.
Main Methods:
- X-ray absorption scattering and Resonant Inelastic X-ray Scattering (RIXS) at the Nickel (Ni) K-edge.
- Analysis of incident energy dependence and x-ray polarization effects.
Main Results:
- dd excitation shows a maximum at the 1s→4pπ transition.
- Excitation intensity correlates with x-ray polarization parallel to the c-axis.
- An insulating gap closing was observed with increasing temperature.
Conclusions:
- The RIXS process involves strong Ni 3d-Ni 4p Coulomb interaction, specifically with Ni 4pπ.
- The '4p-as-spectator' approximation is not applicable.
- Temperature-dependent insulating gap closure indicates a phase transition.
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