Proceedings of the European Symposium on Frontiers in Science and Technology with Synchrotron Radiation

J. Phys. IV France 04 (1994) C9-109-C9-112
DOI: 10.1051/jp4:1994914

Parallel beam powder diffraction study on the A_lC₆₀ system (A=K, Rb)

G. Faigel¹, M. Tegze¹, G. Bortel¹, L. Forró², G. Oszlányi^{2, 3} and P.W. Stephens<sup>4

1</sup>  Research Institute for Solid State Physics, P.O. Box 49, 1525 Budapest, Hungary
²  Laboratoire de Physique des Solides Semicrystallins, IGA, Departement de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
³  on leave from the Research Institute for Solid State Physics, P.O. Box 49, 1525 Budapest, Hungary
⁴  Department of Physics, State University of New York, Stony Brook, NY 11794-3800, U.S.A.

Abstract
We report x-ray powder diffraction studies on Rb_xC₆₀, and K_xC₆₀. It is shown that at room temperature there exist stoichiometric compounds in the Rb_xC₆₀, and K_xC₆₀ systems at the x= 1 composition. Their equilibrium structures are pseudo body centered orthorhombic. The C₆₀-C₆₀ intermolecular separation (9.1 Å) is the shortest among the known alkali- fullerides. A first order phase transition is observed at about 380 K from the high temperature fcc phase to the room temperature orthorhombic phase.

© EDP Sciences 1994