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Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction

C. Schuessler-Langeheine·J. Schlappa·A. Tanaka·Z. Hu·C. F. Chang·E. Schierle·M. Benomar·H. Ott·E. Weschke·G. Kaindl·O. Friedt·G. A. Sawatzky·H. -J. Lin·C. T. Chen·M. Braden·L. H. Tjeng
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Abstract

Strong resonant enhancements of the charge-order and spin-order superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The pronounced photon-energy and polarization dependences of these diffraction intensities allow for a critical determination of the local symmetry of the ordered spin and charge carriers. We found that not only the antiferromagnetic order but also the charge-order superstructure resides within the NiO2 layers; the holes are mainly located on in-plane oxygens surrounding a Ni2+ site with the spins coupled antiparallel in close analogy to Zhang-Rice singlets in the cuprates.

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C. Schuessler-Langeheine, J. Schlappa, A. Tanaka, Z. Hu, C. F. Chang, E. Schierle, M. Benomar, H. Ott, E. Weschke, G. Kaindl, O. Friedt, G. A. Sawatzky, H. -J. Lin, C. T. Chen, M. Braden, L. H. Tjeng. 2005-02-15. Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction. https://doi.org/10.1103/physrevlett.95.156402

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