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arXiv · 1501.02075

Coexistence of localized and itinerant electrons in BaFe2X3 (X = S and Se) revealed by photoemission spectroscopy

D. Ootsuki·N. L. Saini·F. Du·Y. Hirata·K. Ohgushi·Y. Ueda·T. Mizokawa
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Abstract

We report a photoemission study at room temperature on BaFe2X3 (X = S and Se) and CsFe2Se3 in which two-leg ladders are formed by the Fe sites. The Fe 2p core-level peaks of BaFe2X3 are broad and exhibit two components, indicating that itinerant and localized Fe 3d sites coexist similar to KxFe2-ySe2. The Fe 2p core-level peak of CsFe2Se3 is rather sharp and is accompanied by a charge-transfer satellite. The insulating ground state of CsFe2Se3 can be viewed as a Fe2+ Mott insulator in spite of the formal valence of +2.5. The itinerant versus localized behaviors can be associated with the stability of chalcogen p holes in the two-leg ladder structure.

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D. Ootsuki, N. L. Saini, F. Du, Y. Hirata, K. Ohgushi, Y. Ueda, T. Mizokawa. 2015-01-09. Coexistence of localized and itinerant electrons in BaFe2X3 (X = S and Se) revealed by photoemission spectroscopy. https://doi.org/10.1103/physrevb.91.014505

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