Local structure displacements in La1-xCex OBiSSe as a function of Ce substitution

Pugliese G. M., Stramaglia F., Capone F. G., Hacisalihoglu M. Y., Kiyama R., Sogabe R., ...Daha Fazla

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, cilt.147, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 147
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.jpcs.2020.109648
  • Dergi Adı: JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Metadex
  • Anahtar Kelimeler: BiS2-based systems, Superconductivity, Self-doping, Local structure, SUPERCONDUCTIVITY
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

We have investigated the local structure of layered La1-xCexOBiSSe system by Bi L-3 -edge extended X-ray absorption fine structure (EXAFS) measurements for different Ce substitutions. Ce L-3-edge X-ray absorption spectroscopy (XAS) has been used to evaluate the Ce valence responsible for the self-doping in this system. We have found that the local distortion, determined by the separation between two Bi-Ch distances within the BiCh(2)-layer (Ch=S,Se), is quickly suppressed by Ce substitution while the axial Bi-S2 bond elongates. Ce L-3-edge XAS reveals a coexistence of Ce3+ and Ce4+ in which the Ce4+ weight decreases, an indication of a partial breaking of RE-S-Bi (RE=La/Ce) charge transfer channel with Ce substitution. The results suggest that interaction between REO spacer layer and BiCh(2) layer, dictated by the out-of-plane Bi-S2 distance, has a significant role in triggering superconductivity in the title system, with the in-plane distortion controlling the charge mobility within the BiCh(2) -layer.