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Probing La-based nickelates with Ni1s core-level photoelectron spectroscopy

Daisuke Takegami1,2,3,*, Naoki Ito4, Koto Fujinuma2, Masato Yoshimura5, Grace A. Pan6, Dan Ferenc Segedin6, Qi Song6, Hanjong Paik7,8,9, Charles M. Brooks6 et al.

Hanjie Guo3, Alexander C. Komarek3, Takanori Taniguchi10, Masaki Fujita10, Julia A. Mundy6,11, Takashi Mizokawa2, Liu Hao Tjeng3, Berit H. Goodge3, and Atsushi Hariki4

  • *Contact author: dtakegami@tmu.ac.jp
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Phys. Rev. B 114, 185129 – Published 25 September, 2026

DOI: https://doi.org/10.1103/fkvs-lfjm

Abstract

We present a comparative Ni core level photoemission study of La3Ni2O7, Nd3Ni2O7, and LaNiO3 using both the Ni2p and the Ni1s. We address the challenges in analyzing the widely investigated Ni2p spectra arising from the substantial overlap in energy of the Ni2p with the La 3d. We show that, on the other hand, the deep Ni1s core level does provide a clean view on the intrinsic electronic excitations and we highlight its potential to resolve detailed differences in the electronic structure within the strongly correlated Ruddlesden-Popper series Lan+1NinO3n+1.

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Phys. Rev. B 114, 185129– Published 25 September, 2026
  • Received 4 June 2026
  • Revised 13 August 2026
  • Accepted 9 September 2026
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