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Element-Specific Probe of the Magnetic and Electronic Properties of Dy incar-Fullerenes

“…In the difference spectra obtained from the spectrum measured on-resonance and the spectrum measured off-resonance, no significant enhancement of spectral intensity is observed in Dy 2 @C 88 where Dy 5d states are expected. The lack of significant density of states close to the Fermi level is in agreement with a previous Mössbauer study of the same system, which indicates a full charge transfer from Dy to the carbon cage and therefore no electrons in 5d orbitals …”

“…For Dy@C 82 , Mössbauer measurements find paramagnetic relaxation at 4.2 K and an isomer shift consistent with the Dy 3+ state and a full charge transfer to the fullerene cage …”

“…10 For Dy@C 82 , Mo ¨ssbauer measurements find paramagnetic relaxation at 4.2 K and an isomer shift consistent with the Dy 3+ state and a full charge transfer to the fullerene cage. 15 Magnetic susceptibility measurements 12 indicate a paramagnetic relaxation even at 1.8 K with the Dy@C 82 system having a magnetic moment reduced by 13-20% with respect to the full moment value of trivalent Dy. It is also interesting to investigate the valence state of the encaged Dy atom since a valence change from the trivalent to the lower valence state is expected to occur when the coordination number is reduced to less than 4 atoms.…”

Magnetic Moments of the Endohedral Cluster Fullerenes Ho3N@C80 and Tb3N@C80: The Role of Ligand Fields

“…The influence of the electron transfer from M to the carbon cage, the geometric structure of the M k @C 2 n , as well as the location of the metal ion(s) in the cage on the magnetic properties are commonly studied. As shown by ESR spectroscopy, photoemission or Mössbauer spectroscopy, R ions are trivalent in most cases as in Er k @C 82 for k =1 and 22, 3 and Dy@C 2 n (2 n =80, 82, 84) 4. Detailed studies of the fullerene magnetization versus applied field and temperature have confirmed these results 5–11.…”

Magnetische Momente der endohedralen Clusterfullerene Ho3N@C80 und Tb3N@C80 – die Rolle des Ligandenfeldes

“…Mit ESR‐Spektroskopie, Photoemissionsmessungen und der Mößbauer‐Spektroskopie wurde nachgewiesen, dass Lanthanoid‐Ionen in den meisten Fällen dreiwertig sind, z. B. in Er k @C 82 (mit k =1 und 2)2, 3 und in Dy@C 2 n (2 n =80, 82, 84) 4. Detaillierte Untersuchungen der Magnetisierung von Fullerenen in Abhängigkeit von Temperatur und Magnetfeld bestätigten diesen Befund 5–11.…”