The superconductivity observed in rare-earth C60 fullerides REx C60 (RE = Yb and Sm) and La - C60 compounds are described. It is shown that RE2.75 C60's do not superconduct and the true superconducting phase in Yb - C60 fulleride resides in the t1 g band. No superconductivity is observed in Sm - C60 fullerides. The phase sequence between Yb - C60 fullerides and Sm - C60 ones as a function of the intercalant concentration is shown to be greatly different, although Yb and Sm are the same family of divalent rare-earth elements. This seems to explain the loss of superconductivity in Smx C60, and suggests that the true superconducting phase is most likely Ybx C60(x > 3) with the primitive cubic lattice. In addition, the superconductivity observed in C60 with La is shown to result from La2 C3 carbides with two transition temperatures.
|Journal||Science and Technology of Advanced Materials|
|Issue number||SUPPL. 1|
|Publication status||Published - 2006 Jan 1|
- Fullerenes and related materials
ASJC Scopus subject areas
- Materials Science(all)