Unusual superexchange pathways in an NiS2 triangular lattice with negative charge-transfer energy

K. Takubo, T. Mizokawa, J. Y. Son, Y. Nambu, S. Nakatsuji, Y. Maeno

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We have studied the electronic structure of the Ni triangular lattice in NiGa2S4 using photoemission spectroscopy and subsequent model calculations. The cluster-model analysis of the Ni 2p core-level spectrum shows that the S 3p to Ni 3d charge-transfer energy is ∼-1eV and the ground state is dominated by the d9L configuration (L is a S 3p hole). Cell perturbation analysis for the NiS2 triangular lattice indicates that the strong S 3p hole character of the ground state provides the enhanced superexchange interaction between the third-nearest-neighbor sites.

Original languageEnglish
Article number037203
JournalPhysical Review Letters
Issue number3
Publication statusPublished - 2007 Jul 19


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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