XAFS study on metal endohedral fullerenes

Abstract

Structure of metal endohedral fullerenes is studied by XAFS and XANES. The Sc-Sc distance of 2.23(1) Å determined from Sc Kedge XAFS supports the formation of a triangular Sc 3 cluster in Sc 3 @C 82 as is found by MEM analysis for the X-ray diffraction. Gd L III -edge XAFS of Gd@C 82 shows that the first and the second neigboring Gd-C distances are 2.51(2) and 2.85(4) Å, respectively. The La-La distance of La 2 @C 80 has been determined to be 3.90(1) Å at 40 K. This value does not change when increasing temperature [3.90(2) Å at 240 K]. The position and the valenece of the Eu atom in Eu@C 60 are also discussed based on Eu L III -edge XAFS and XANES.

Structural and electronic properties ofCe@C82

“…16,30,31 On the other hand, r Ce-C(2) is slightly smaller than those for Dy@C 82 ͓2.83͑2͒ Å͔, Gd@C 82 isomer I ͓2.77͑3͒ Å͔, and La@C 82 isomer I ͓2.94͑7͒ Å͔. 16,30,31 The structural parameters obtained from EXAFS show that the Ce@C 82 molecule is not damaged by thermal deposition when a thin film is formed; this finding is also supported by the Raman spectra as described in Sec. III B.…”

Valence and core photoemission in M@C60(M = Be, Mg, Ca)

“…Among the various properties of these systems, the photoionization process has shown especially peculiar behaviour for M@C 60 , particularly as regards the cross section and the asymmetry parameter profiles. Although experimental measures are very sparse [6,[11][12][13], there is rather active theoretical research in this field. In particular, a wealth of shape resonances with very intense and sharp peaks both in the valence [14][15][16] and metal core ionization [17,18] of M@C 60 has been found.…”