Abstract
Superconducting transition temperature (Tc) and crystal structure of binary alkali-metal doped fullerenes have been studied. A new relationships between Tc and lattice constant (a0) is presented over a wide range of a0 for superconducting face-centered cubic (fcc) M3C60 phases, using a new series of superconductors: Na2MC60 (Tc=12 K for M=rmK, Tc=2.5 K for M=Rb, Tc = 2.K for M=Cs and Li2CsC60 (Tc=12 K). The site selectivity of the doped cationic elements for the two tetrahedral and one octahedral interstitial sites per C60 in the fcc lattice is discussed in detail on a basis of refinements of the measured X-ray patterns. The departure from the previous relationship between Tc and a0 for lattice parameters smaller than that of pristine C60 and the Tc saturation tendency in the large lattice parameter region may provide new insights into what controls superconductivity in these materials.
Original language | English |
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Pages (from-to) | 3240-3245 |
Number of pages | 6 |
Journal | Synthetic Metals |
Volume | 56 |
Issue number | 2-3 |
DOIs | |
Publication status | Published - 1993 Apr 5 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry