We have studied the electronic structure of CsW2O6 across its metal-insulator transition by means of hard/soft x-ray photoelectron spectroscopy. In the high-temperature metallic phase, the W 5d band exhibits a clear Fermi edge. The W 4 f7/2 and 4 f5/2 core-level peaks are accompanied by shoulders on their lower binding energy side. The shoulder and main peaks, respectively, are attributed to the well-and poorly screened final states where the screening is due to the W 5d electronic states in the vicinity of the chemical potential. In going from 300 to 180 K (across the metal-insulator transition), a band gap of about 0.2 eV is created at the Fermi level. The origin of the band gap can be assigned to the trimerization of the W sites. The W 4 f and 5d spectra exclude the possibility of charge disproportionation and suggest moderate electronic correlation effects.
Electronic structure reconstruction by trimer formation in CsW2O6 studied by x-ray photoelectron spectroscopy / Nakamura, R; Takegami, D; Melendez-Sans, A; Tjeng, Lh; Okawa, M; Miyoshino, T; Saini, Nl; Kitamura, M; Shiga, D; Kumigashira, H; Yoshimura, M; Tsuei, Kd; Okamoto, Y; Mizokawa, T. - In: PHYSICAL REVIEW. B. - ISSN 2469-9950. - 106:19(2022). [10.1103/PhysRevB.106.195104]
Electronic structure reconstruction by trimer formation in CsW2O6 studied by x-ray photoelectron spectroscopy
Saini, NL;
2022
Abstract
We have studied the electronic structure of CsW2O6 across its metal-insulator transition by means of hard/soft x-ray photoelectron spectroscopy. In the high-temperature metallic phase, the W 5d band exhibits a clear Fermi edge. The W 4 f7/2 and 4 f5/2 core-level peaks are accompanied by shoulders on their lower binding energy side. The shoulder and main peaks, respectively, are attributed to the well-and poorly screened final states where the screening is due to the W 5d electronic states in the vicinity of the chemical potential. In going from 300 to 180 K (across the metal-insulator transition), a band gap of about 0.2 eV is created at the Fermi level. The origin of the band gap can be assigned to the trimerization of the W sites. The W 4 f and 5d spectra exclude the possibility of charge disproportionation and suggest moderate electronic correlation effects.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.