Negative thermal expansion in the mixed valence ytterbium fullende, Yb 2.75C60

Serena Margadonna, J. Arvanitidis, Konstantinos Papagelis, Kosmas Prassides

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)


The powder synchrotron X-ray diffraction technique was used to study the temperature evolution of the structural properties of the mixed valence rare earth fulleride, Yb2.75C60, in the temperature range 5-295 K. The large lattice expansion (negative thermal expansion) on cooling below 60 K provides an unambiguous signature of a temperature-induced valence transition of the Yb atoms. The transformation is of electronic origin and is driven by the coupling of the Yb 4f band and the t1u band of C60. It is analogous to that observed at lower temperatures in Sm2.75C 60, but it is absent when the electronically active 4f sublattice is missing in the related alkaline earth fulleride, Ca2.75C 60.

Original languageEnglish
Pages (from-to)4474-4478
Number of pages5
JournalChemistry of Materials
Issue number17
Publication statusPublished - 2005 Aug 23

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry


Dive into the research topics of 'Negative thermal expansion in the mixed valence ytterbium fullende, Yb 2.75C60'. Together they form a unique fingerprint.

Cite this