Charge-transfer properties and electron dynamics in ferromagnetic CoS 2

作者：Mahmoud Abdel‐Hafiez, Fredrik O. L. Johansson, Anwesha Chakraborty, Martin Pavelka, Anirudha Ghosh, Д. А. Чареев, A. N. Vasiliev, Å. Edström, Anna Delin, Olle Eriksson, Debjani Karmakar, Dibya Phuyal · 发表于：Physical review. B./Physical review. B · 年份：2025 · DOI：10.1103/vg4c-h785 · 被引用次数：2 · 研究领域：Heusler alloys: electronic and magnetic properties、Magnetic and transport properties of perovskites and related materials、Advanced Condensed Matter Physics

We investigated the element-specific electronic structure and charge-carrier dynamics of a single-crystal ferromagnet CoS 2 with complementary x-ray spectroscopy techniques. Hard x-ray photoemission (HAXPES) is used to provide crucial information on the bulk electronic structure and chemical bonding in CoS 2 that is compared against the isoelectronic paramagnet CoSe 2 . The Co 1 s core-level line shows several satellite features for CoS 2 , showing explicit charge-transfer processes and local screening of the core hole by S ligands, whereas no such features are observed in CoSe 2 . The satellite structures indicate the electronic configuration of divalent Co 2 + as a combination of d 8 Ḻ and d 9 Ḻ 2 in addition to the nominal ionic d 7 state, where Ḻ represents an S 3 p hole. We employ resonant Auger spectroscopy across the S K -edge for CoS 2 to obtain electron delocalization times to adjacent Co atomic sites. The fast carrier dynamics are attributed to strongly screened Coulomb interactions and hence a facile carrier delocalization. The strong hybridization formed between the Co 3 d and S 3 p states with pronounced charge-transfer character reflects a self-doped system with a finite density n of holes at the sulfur site ( Ḻ n ), in line with recent...