@article{848b615130404fb482d780aa16cc2275,
title = "Anomalous metallic state with strong charge fluctuations in BaxTi8 O16+δ revealed by hard x-ray photoemission spectroscopy",
abstract = "We have studied a charge-orbital driven metal-insulator transition (MIT) in hollandite-type BaxTi8O16+δ by means of hard x-ray photoemission spectroscopy (HAXPES). The Ti 2p HAXPES indicates strong Ti3+/Ti4+ charge fluctuation in the metallic phase above the MIT temperature. The metallic phase is characterized by a power-law spectral function near the Fermi level which would be a signature of bad metal with non-Drude polaronic behavior. The power-law spectral shape is associated with the large Seebeck coefficient of the metallic phase in BaxTi8O16+δ.",
author = "S. Dash and T. Kajita and M. Okawa and T. Saitoh and E. Ikenaga and Saini, {N. L.} and T. Katsufuji and T. Mizokawa",
note = "Funding Information: The synchrotron radiation experiment was performed with the approval of SPring-8 (2017A1015). This work was supported by CREST-JST (Grant No. JPMJCR15Q2) and KAKENHI from JSPS (Grants No. 17K05502 and No. 16H04020). Funding Information: We would like to thank T. Enomoto, K. Takahashi, and R. Takayanagi for the assistance of the HAXPES experiments. The synchrotron radiation experiment was performed with the approval of SPring-8 (2017A1015). This work was supported by CREST-JST (Grant No. JPMJCR15Q2) and KAKENHI from JSPS (Grants No. 17K05502 and No. 16H04020). Publisher Copyright: {\textcopyright} 2018 American Physical Society.",
year = "2018",
month = apr,
day = "10",
doi = "10.1103/PhysRevB.97.165116",
language = "English",
volume = "97",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "16",
}