Anomalous state sandwiched between fermi liquid and charge ordered mott-insulating phases of Ti4O7

M. Taguchi, A. Chainani, M. Matsunami, Ritsuko Eguchi, Y. Takata, M. Yabashi, K. Tamasaku, Y. Nishino, T. Ishikawa, S. Tsuda, S. Watanabe, C. T. Chen, Y. Senba, H. Ohashi, K. Fujiwara, Y. Nakamura, H. Takagi, S. Shin

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Abstract

The Magnéli phase Ti4O7 exhibits two sharp jumps in resistivity with coupled structural transitions as a function of temperature at Tc1∼142K and Tc2=154K. We have studied electronic structure changes across the two transitions using 7 eV laser, soft x-ray, and hard x-ray (HX) photoemission spectroscopy (PES). Ti 2p-3d resonant PES and HX PES show a clear metallic Fermi edge and mixed valency above Tc2. The low temperature phase below Tc1 shows a clear insulating gap of ∼100meV. The intermediate phase between Tc1 and Tc2 indicates a pseudogap coexisting with remnant coherent states. HX PES and complementary calculations have confirmed the coherent screening in the strongly correlated intermediate phase. The results suggest the existence of a highly anomalous state sandwiched between the mixed-valent Fermi liquid and charge ordered Mott-insulating phase in Ti4O7.

Original languageEnglish
Article number106401
JournalPhysical Review Letters
Volume104
Issue number10
DOIs
Publication statusPublished - Mar 8 2010
Externally publishedYes

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Fermi liquids
photoelectric emission
spectroscopy
x rays
screening
electronic structure
electrical resistivity
lasers
temperature

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Anomalous state sandwiched between fermi liquid and charge ordered mott-insulating phases of Ti4O7. / Taguchi, M.; Chainani, A.; Matsunami, M.; Eguchi, Ritsuko; Takata, Y.; Yabashi, M.; Tamasaku, K.; Nishino, Y.; Ishikawa, T.; Tsuda, S.; Watanabe, S.; Chen, C. T.; Senba, Y.; Ohashi, H.; Fujiwara, K.; Nakamura, Y.; Takagi, H.; Shin, S.

In: Physical Review Letters, Vol. 104, No. 10, 106401, 08.03.2010.

Research output: Contribution to journalArticle

Taguchi, M, Chainani, A, Matsunami, M, Eguchi, R, Takata, Y, Yabashi, M, Tamasaku, K, Nishino, Y, Ishikawa, T, Tsuda, S, Watanabe, S, Chen, CT, Senba, Y, Ohashi, H, Fujiwara, K, Nakamura, Y, Takagi, H & Shin, S 2010, 'Anomalous state sandwiched between fermi liquid and charge ordered mott-insulating phases of Ti4O7', Physical Review Letters, vol. 104, no. 10, 106401. https://doi.org/10.1103/PhysRevLett.104.106401
Taguchi, M. ; Chainani, A. ; Matsunami, M. ; Eguchi, Ritsuko ; Takata, Y. ; Yabashi, M. ; Tamasaku, K. ; Nishino, Y. ; Ishikawa, T. ; Tsuda, S. ; Watanabe, S. ; Chen, C. T. ; Senba, Y. ; Ohashi, H. ; Fujiwara, K. ; Nakamura, Y. ; Takagi, H. ; Shin, S. / Anomalous state sandwiched between fermi liquid and charge ordered mott-insulating phases of Ti4O7. In: Physical Review Letters. 2010 ; Vol. 104, No. 10.
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