@article{oai:repo.qst.go.jp:00081981,
 author = {Ishii, Kenji and Asano, Shun and Ashida, Masumi and Fujita, Masaki and Yu, Biqiong and Greven, Martin and Okamoto, Jun and Di-Jing, Huang and Kenji, Ishii},
 issue = {2},
 journal = {Physical Review Materials},
 month = {Feb},
 note = {We report a Cu K- and L3-edge resonant inelastic x-ray scattering study of charge and spin excitations of bulk Nd2−xCexCuO4, with a focus on post-growth annealing effects. For the parent compound Nd2CuO4 (x = 0), a clear charge-transfer gap is observed in the as-grown state, whereas the charge excitation spectra indicate that electrons are doped in the annealed state. This is consistent with the observation that annealed thin-film and polycrystalline samples of RE2CuO4 (RE = rare earth) can become metallic and superconducting at sufficiently high electron concentrations without Ce doping. For x = 0.16, a Ce concentration for which it is known that oxygen reduction destroys long-range antiferromagnetic order and induces superconductivity, we find that the high-energy spin excitations of non-superconducting as-grown and superconducting annealed crystals are nearly identical. This finding is in stark contrast to the significant changes in the low-energy spin excitations previously observed via neutron scattering.},
 title = {Post-growth annealing effects on charge and spin excitations in Nd2−xCexCuO4},
 volume = {5},
 year = {2021}
}