Crystal structure of the pyrochlore oxide superconductor KOs 2O6

Jun Ichi Yamaura, Shigeki Yonezawa, Yuji Muraoka, Zenji Hiroi

Research output: Contribution to journalArticlepeer-review

97 Citations (Scopus)


We report the single-crystal X-ray analysis of the structure of the pyrochlore oxide superconductor KOs2O6. The structure was identified as the β-pyrochlore structure with space group Fd3̄m and lattice constant a=10.089(2)Å at 300K: the K atom is located at the 8b site, not at the 16d site as in conventional pyrochlore oxides. We found an anomalously large atomic displacement parameter Uiso=0.0735(8)Å2 at 300K for the K cation, which suggests that the K cation weakly bound to an oversized Os12O18 cage exhibits intensive rattling, as recently observed for clathrate compounds. The rattling of A cations is a common feature in the series of β-pyrochlore oxide superconductors AOs2O 6 (A=Cs, Rb and K), and is greatest for the smallest K cation.

Original languageEnglish
Pages (from-to)336-340
Number of pages5
JournalJournal of Solid State Chemistry
Issue number1
Publication statusPublished - Jan 2006
Externally publishedYes


  • Crystal structure
  • Pyrochlore oxides
  • Rattling
  • Superconductor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry


Dive into the research topics of 'Crystal structure of the pyrochlore oxide superconductor KOs 2O6'. Together they form a unique fingerprint.

Cite this