Effect of molecular intercalation on the local structure of superconducting Nax(NH3)yMoSe2 system

L. Simonelli, E. Paris, Takanori Wakita, C. Marini, Kensei Terashima, X. Miao, W. Olszewski, N. Ramanan, D. Heinis, Yoshihiro Kubozono, Takayoshi Yokoya, N. L. Saini

Research output: Contribution to journalArticle

Abstract

We have studied the local structure of layered Nax(NH3)yMoSe2 system by Mo K-edge extended X-ray absorption fine structure (EXAFS) measurements performed as a function of temperature. We find that molecular intercalation in MoSe2 largely affects the Mo-Se network while Mo-Mo seems to sustain small changes. The Einstein temperature (ΘE of Mo-Mo distance hardly changes (∼264 K) indicating that bond strength of this distance remains unaffected by intercalation. On the other hand, Mo-Se distance suffers a softening, revealed by the decrease of ΘE from ∼364 K to ∼350 K. The results indicate that Na+ ion transported by NH3 molecules may enter between the two MoSe-layers resulting reduced Se-Se coupling. Therefore, increased hybridization between Se 4p and Mo 4d orbitals due to inter-layer disorder is the likely reason of metallicity in intercalated MoSe2 and superconductivity at low temperature.

Original languageEnglish
Pages (from-to)70-74
Number of pages5
JournalJournal of Physics and Chemistry of Solids
Volume111
DOIs
Publication statusPublished - Dec 1 2017

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Keywords

  • Dichalcogenides
  • Intercalation effect
  • Local disorder
  • Superconductivity

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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