High pressure polymerization of the Li-intercalated fulleride Li{sub 3}CsC{sub 60}

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm990346c· OSTI ID:20001162

Margadonna, S; Prassides, K; Knudsen, K D; Hanfland, M; Kosaka, Mayumi; Tanigaki, Katsumi

The structural features of the superconducting Li{sub 3}CsC{sub 60} fulleride are studied by synchrotron X-ray powder diffraction as a function of pressure and temperature. In contrast with the behavior of Li{sub 2}CsC{sub 60} shows a phase transition below room temperature from fcc (space group Fm{bar 3}m) to an orientationally ordered primitive cubic phase (space group Pa{bar 3}), isostructural with the metastable phases of Na{sub 2}A{prime}C{sub 60}. Despite the slow cooling protocols adopted, the system shows no other phase transitions even after prolonged standing at 200 K. The pressure dependence of the structure of Li{sub 3}CsC{sub 60} at ambient temperature was followed up to 8.12 GPa. A phase transition occurs at 0.72 GPa to a low symmetry fullerene bridged polymeric phase with short center-to-center interfullerene separations of {approximately}9.38 {angstrom}. This phase was found to be monoclinic (space group P2{sub 1}/a), isostructural with the low-temperature polymer phase of Na{sub 2}RbC{sub 60} and the high-pressure polymer phase of Na{sub 2}CsC{sub 60}. The pressure evolution of the monoclinic lattice constants reveals a highly incompressible, tightly packed, and strongly anisotropic polymeric structure.

• Research Organization: Univ. of Sussex (GB)
• OSTI ID: 20001162
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 10 Vol. 11; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CESIUM CARBIDES
CRYSTAL-PHASE TRANSFORMATIONS
FULLERENES
HIGH PRESSURE
LITHIUM CARBIDES
MONOCLINIC LATTICES
POLYMERIZATION